Performance

Titanium targets low-overhead MITM proxying: connection pooling, HTTP/2 multiplexing, and buffer reuse. Numbers below are Release measurements with RpsLoadProbe (and BenchmarkDotNet / Basic example where noted). Publishable tables cite GitHub Actions medians on matched 4 vCPU / 16 GiB runners. Absolute RPS still varies by OS kernel, TLS, and MsQuic packaging — compare within a table, not across Windows vs Linux.

Control arms: nginx (native C reverse-proxy ceiling; Linux is authoritative) and YARP (Yarp.ReverseProxy, managed .NET reverse proxy). Neither can MITM (no CONNECT / forged certs). FiddlerCore is not compared (commercial debugger license; not a throughput peer).

For pooling knobs and certificate first-visit tuning, see Performance and pooling. For the local cool A/B lab, laptop tables, and profiling notes, see Performance Profiling.

Measurement environment

Both OS use the standard public-repo GitHub-hosted runner class (4 vCPU / 16 GiB / 14 GB SSD). Same harness knobs (workflow_dispatch RPS saturation: warmup 2s / measure 8s; concurrency 8, 16, 32, 64; median of 3 repeats). Every --ramp arm is three OS processes (parent load generator + origin child + proxy child), except origin-direct arms (load gen + origin only). Prefer TWP÷YARP / TWP÷nginx ratios over absolute RPS.

Laptop High-perf / cool-paired Windows numbers live on Performance Local Lab. Do not mix those absolutes into the tables below.

Windows (GitHub-hosted `windows-latest`)


OS	Windows Server (GitHub-hosted `windows-latest`)
CPU	4 logical processors
RAM	16 GiB
Runtime	.NET 10.0.x
nginx	nginx/Windows 1.31.3 (same-OS only; no QUIC)
YARP	Yarp.ReverseProxy 2.3.0
Harness	RpsLoadProbe Release; median of 3 repeats

Linux (GitHub-hosted `ubuntu-latest`)


OS	Ubuntu 24.04.x LTS
CPU	4 logical processors (AMD EPYC; runners this pass were 7763 / 9V74)
RAM	16 GiB
Runtime	.NET 10.0.11
nginx	nginx/1.31.4 (nginx.org mainline, `--with-http_v3_module`)
YARP	Yarp.ReverseProxy 2.3.0
Harness	RpsLoadProbe Release; median of 3 repeats where noted

Saturation control

Calibration for the shared 4 vCPU loopback shape: how close client + origin are to saturated before ranking reverse peers. Tiny keep-alive GET. Median of 3 repeats @ 9d7c2966 — 32866709227. Warmup 2s / measure 8s; concurrency 8, 16, 32, 64. Block A % of origin-HttpClient uses median peak RPS. Blocks B/C use peer÷YARP / ÷nginx on median peak (not % of H1 origin). RPS cells embed median RSS / CPU for the proxy child plus its full descendant tree (serve-proxy → nginx master → workers); origin-direct samples the origin child. Product matrices below use matched dotnet-httpclient only (not bombardier). H3→H1 (saturation Block C): Win TWP RSS 103 MiB vs YARP 119 (0.87×); Linux 142 vs 181 (0.78×). RPS vs YARP (0.99× / 1.1×).

pwsh tools/RpsLoadProbe/run-rps.ps1 -Mode compare-saturation

Block A — H1 plain

Arm	Generator	Notes
`origin-direct`	`dotnet-httpclient`	No proxy — origin ceiling under the same client used for publishable ratios
`origin-direct-bombardier`	`bombardier`	External client check (CI installs bombardier)
`bare-reverse-http1`	`dotnet-httpclient`	Thin C# H1 reverse (`BareHttp1ReverseProxy`) — .NET runtime / loopback ceiling for a three-process reverse hop; not a product peer
`nginx-reverse-http1` / `yarp-reverse-http1` / `twp-reverse-http1`	`dotnet-httpclient`	Product peers (medals among these three only)

Windows (windows-latest)

Arm	Generator	Sustain	Peak	% of origin-HttpClient
origin-direct	dotnet-httpclient	50,717 _{(53 MiB / 41.6% CPU)}	50,717 _{(53 MiB / 41.6% CPU)}	100.0%
origin-direct-bombardier	bombardier	38,335 _{(55 MiB / 22.7% CPU)}	38,335 _{(55 MiB / 22.7% CPU)}	75.6%
bare-reverse-http1	dotnet-httpclient	25,467 _{(55 MiB / 46.5% CPU)}	25,467 _{(55 MiB / 46.5% CPU)}	50.2%
nginx-reverse-http1	dotnet-httpclient	13,259 _{(121 MiB / 25.0% CPU)}	13,422 _{(121 MiB / 25.0% CPU)}	26.5%
yarp-reverse-http1	dotnet-httpclient	21,331 _{(89 MiB / 49.9% CPU)}	21,331 _{(89 MiB / 49.9% CPU)}	42.1%
twp-reverse-http1	dotnet-httpclient	🥇 25,358 _{(75 MiB / 49.2% CPU)}	25,358 _{(75 MiB / 49.2% CPU)}	50.0%

Linux (ubuntu-latest)

Arm	Generator	Sustain	Peak	% of origin-HttpClient
origin-direct	dotnet-httpclient	68,992 _{(78 MiB / 41.8% CPU)}	68,992 _{(78 MiB / 41.8% CPU)}	100.0%
origin-direct-bombardier	bombardier	41,996 _{(78 MiB / 34.4% CPU)}	41,996 _{(78 MiB / 34.4% CPU)}	60.9%
bare-reverse-http1	dotnet-httpclient	32,077 _{(60 MiB / 45.0% CPU)}	32,077 _{(60 MiB / 45.0% CPU)}	46.5%
nginx-reverse-http1	dotnet-httpclient	🥇 38,039 _{(72 MiB / 40.9% CPU)}	38,039 _{(72 MiB / 40.9% CPU)}	55.1%
yarp-reverse-http1	dotnet-httpclient	26,736 _{(113 MiB / 49.2% CPU)}	26,736 _{(113 MiB / 49.2% CPU)}	38.8%
twp-reverse-http1	dotnet-httpclient	31,431 _{(84 MiB / 50.0% CPU)}	31,431 _{(84 MiB / 50.0% CPU)}	45.6%

Reverse peers are about 50–46% of the origin-direct HttpClient peak on this runner class (Win TWP 50.0%, Lin TWP 45.6%). Prefer the % column over absolute RPS across runs. Bare and origin-direct are controls (not medal peers).

Block B — H2 TLS→H1

Peer ratios (÷YARP / ÷nginx) on median peak; RPS cells embed (MiB / CPU%).

Windows (windows-latest)

Arm	Generator	Sustain	Peak	÷YARP	÷nginx
nginx-reverse-http2	dotnet-httpclient	8,264 _{(248 MiB / 24.8% CPU)}	8,411 _{(248 MiB / 24.8% CPU)}	0.29×	1×
yarp-reverse-http2	dotnet-httpclient	29,096 _{(95 MiB / 53.0% CPU)}	29,096 _{(95 MiB / 53.0% CPU)}	1×	3.46×
twp-reverse-http2-cleartext	dotnet-httpclient	🥇 35,180 _{(96 MiB / 52.0% CPU)}	35,180 _{(96 MiB / 52.0% CPU)}	1.21×	4.18×

Linux (ubuntu-latest)

Arm	Generator	Sustain	Peak	÷YARP	÷nginx
nginx-reverse-http2	dotnet-httpclient	14,490 _{(97 MiB / 19.4% CPU)}	14,490 _{(97 MiB / 19.4% CPU)}	0.51×	1×
yarp-reverse-http2	dotnet-httpclient	28,448 _{(120 MiB / 49.0% CPU)}	28,448 _{(120 MiB / 49.0% CPU)}	1×	1.96×
twp-reverse-http2-cleartext	dotnet-httpclient	🥇 33,751 _{(120 MiB / 51.7% CPU)}	33,751 _{(120 MiB / 51.7% CPU)}	1.19×	2.33×

Block C — H3→H1

Same layout as Block B. Requires QuicListener; nginx only with http_v3_module (Windows nginx has no QUIC).

Windows (windows-latest)

Arm	Generator	Sustain	Peak	÷YARP	÷nginx
nginx-reverse-http3-cleartext	dotnet-httpclient	Not possible (no QUIC)	Not possible	—	—
yarp-reverse-http3-cleartext	dotnet-httpclient	14,549 _{(119 MiB / 50.8% CPU)}	15,166 _{(119 MiB / 50.8% CPU)}	1×	—
twp-reverse-http3-cleartext	dotnet-httpclient	🥇 15,028 _{(103 MiB / 46.5% CPU)}	15,028 _{(103 MiB / 46.5% CPU)}	0.99×	—

Linux (ubuntu-latest)

Arm	Generator	Sustain	Peak	÷YARP	÷nginx
nginx-reverse-http3-cleartext	dotnet-httpclient	0 _{(103 MiB / 22.4% CPU)}	15,186 _{(103 MiB / 22.4% CPU)}	0.85×	1×
yarp-reverse-http3-cleartext	dotnet-httpclient	17,856 _{(181 MiB / 49.5% CPU)}	17,856 _{(181 MiB / 49.5% CPU)}	1×	1.18×
twp-reverse-http3-cleartext	dotnet-httpclient	🥇 20,378 _{(142 MiB / 50.4% CPU)}	20,378 _{(142 MiB / 50.4% CPU)}	1.14×	1.34×

How to read the tables

Reverse = bare transparent fixed-forward (no TWP plugins / interception). nginx knobs match TWP/YARP streaming (keepalive 256, proxy_buffering off). MITM = TWP-only table on the same Client×Origin wires: Lite = no-op handlers (unchanged-lite finish may reuse reverse relay); Full = mutating handlers (x-twp-rps-probe) forcing decode/re-encode. nginx/YARP cannot MITM. HTTP/3 has no cleartext client (QUIC always encrypted).
Sustainable = last concurrency that still met error/latency SLOs. Peak = highest RPS in that ramp.
🥇 = best among TWP / nginx / YARP on Reverse rows (or saturation blocks): highest RPS; on an RPS tie, lower Memory (RSS) then lower CPU%. MITM is TWP-only. Lite÷Reverse / Full÷Reverse = TWP MITM lite or full sustain ÷ TWP Reverse sustain on the same Client×Origin from the same compare-product job.
Not possible = product cannot do that path. Not measured = path exists but no published number yet for that OS.
Product refresh: compare-product @ c71937a2 — 32960766249. Heavier/saturation/tls: 32866709227, 32871900682, 32866714851, 32866717729, 32866720742, 32866723562.

pwsh tools/RpsLoadProbe/run-rps.ps1 -Mode compare-product
pwsh tools/RpsLoadProbe/run-rps.ps1 -Mode compare-bodies
pwsh tools/RpsLoadProbe/run-rps.ps1 -Mode compare-post
pwsh tools/RpsLoadProbe/run-rps.ps1 -Mode compare-lossy
pwsh tools/RpsLoadProbe/run-rps.ps1 -Mode compare-tls-cost
pwsh tools/RpsLoadProbe/run-rps.ps1 -Mode compare-arch
pwsh tools/RpsLoadProbe/run-rps.ps1 -Mode compare-saturation

Windows — Titanium vs nginx vs YARP

Client / origin: HTTP version and whether TLS is used (plain = cleartext, TLS = encrypted, QUIC = HTTP/3).

Reverse

Median of 3 repeats on windows-latest (4 vCPU / 16 GiB). Bare reverse 5×5 @ c71937a2 — compare-product 32960766249. Warmup 2s / measure 8s; concurrency 8, 16, 32, 64. Prefer TWP÷peer ratios over absolute RPS. RPS cells include median RSS / CPU at the peak-RPS step as <br><sub>(MiB / CPU%)</sub>. nginx terminate peers use keepalive 256 + streaming buffers. Laptop High-perf / cool-paired numbers stay on the local lab.

Load generators: Reverse inbound H3 arms use dotnet-httpclient (http_version=3.0, RequestVersionExact). nginx/Windows is same-OS only (no QUIC).

Client	Origin	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
HTTP/1 · plain	HTTP/1 · plain	🥇 41025 _{(72 MiB / 48.1% CPU)}	🥇 41025 _{(72 MiB / 48.1% CPU)}	25024 _{(121 MiB / 24.8% CPU)}	25024 _{(121 MiB / 24.8% CPU)}	34609 _{(86 MiB / 48.4% CPU)}	34609 _{(86 MiB / 48.4% CPU)}
HTTP/1 · plain	HTTP/1 · TLS	🥇 34712 _{(81 MiB / 50.5% CPU)}	🥇 34712 _{(81 MiB / 50.5% CPU)}	Not possible	Not possible	30528 _{(99 MiB / 50.8% CPU)}	30528 _{(99 MiB / 50.8% CPU)}
HTTP/1 · plain	HTTP/2 · plain	🥇 55322 _{(101 MiB / 47.8% CPU)}	🥇 55322 _{(101 MiB / 47.8% CPU)}	Not possible	Not possible	52232 _{(92 MiB / 51.1% CPU)}	52232 _{(92 MiB / 51.1% CPU)}
HTTP/1 · plain	HTTP/2 · TLS	🥇 49471 _{(107 MiB / 48.5% CPU)}	🥇 49471 _{(107 MiB / 48.5% CPU)}	Not possible	Not possible	46990 _{(100 MiB / 49.7% CPU)}	46990 _{(100 MiB / 49.7% CPU)}
HTTP/1 · plain	HTTP/3 · QUIC	🥇 27928 _{(112 MiB / 50.8% CPU)}	🥇 27928 _{(112 MiB / 50.8% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	27476 _{(124 MiB / 51.6% CPU)}	27476 _{(124 MiB / 51.6% CPU)}
HTTP/1 · TLS	HTTP/1 · plain	🥇 34140 _{(83 MiB / 43.9% CPU)}	🥇 34140 _{(83 MiB / 43.9% CPU)}	16331 _{(137 MiB / 24.8% CPU)}	16519 _{(137 MiB / 24.8% CPU)}	29749 _{(101 MiB / 49.0% CPU)}	29749 _{(101 MiB / 49.0% CPU)}
HTTP/1 · TLS	HTTP/1 · TLS	🥇 31041 _{(83 MiB / 46.6% CPU)}	🥇 31041 _{(83 MiB / 46.6% CPU)}	Not possible	Not possible	27018 _{(101 MiB / 50.0% CPU)}	27018 _{(101 MiB / 50.0% CPU)}
HTTP/1 · TLS	HTTP/2 · plain	🥇 43769 _{(110 MiB / 47.5% CPU)}	🥇 43769 _{(110 MiB / 47.5% CPU)}	Not possible	Not possible	43070 _{(109 MiB / 49.2% CPU)}	43070 _{(109 MiB / 49.2% CPU)}
HTTP/1 · TLS	HTTP/2 · TLS	🥇 40108 _{(114 MiB / 47.9% CPU)}	🥇 40108 _{(114 MiB / 47.9% CPU)}	Not possible	Not possible	39005 _{(106 MiB / 48.0% CPU)}	39005 _{(106 MiB / 48.0% CPU)}
HTTP/1 · TLS	HTTP/3 · QUIC	🥇 24269 _{(113 MiB / 49.6% CPU)}	🥇 24269 _{(113 MiB / 49.6% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	23450 _{(128 MiB / 50.8% CPU)}	23450 _{(128 MiB / 50.8% CPU)}
HTTP/2 · plain	HTTP/1 · plain	🥇 54074 _{(90 MiB / 51.9% CPU)}	🥇 54074 _{(90 MiB / 51.9% CPU)}	Not possible	Not possible	49807 _{(85 MiB / 51.8% CPU)}	49807 _{(85 MiB / 51.8% CPU)}
HTTP/2 · plain	HTTP/1 · TLS	🥇 46754 _{(101 MiB / 52.0% CPU)}	🥇 46754 _{(101 MiB / 52.0% CPU)}	Not possible	Not possible	41956 _{(91 MiB / 50.6% CPU)}	41956 _{(91 MiB / 50.6% CPU)}
HTTP/2 · plain	HTTP/2 · plain	🥇 119261 _{(72 MiB / 35.1% CPU)}	🥇 119261 _{(72 MiB / 35.1% CPU)}	Not possible	Not possible	89148 _{(97 MiB / 52.7% CPU)}	89148 _{(97 MiB / 52.7% CPU)}
HTTP/2 · plain	HTTP/2 · TLS	🥇 102054 _{(82 MiB / 37.2% CPU)}	🥇 102054 _{(82 MiB / 37.2% CPU)}	Not possible	Not possible	77568 _{(104 MiB / 47.5% CPU)}	77568 _{(104 MiB / 47.5% CPU)}
HTTP/2 · plain	HTTP/3 · QUIC	🥇 42180 _{(135 MiB / 53.8% CPU)}	🥇 42180 _{(135 MiB / 53.8% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	40400 _{(131 MiB / 51.8% CPU)}	40400 _{(131 MiB / 51.8% CPU)}
HTTP/2 · TLS	HTTP/1 · plain	🥇 51831 _{(100 MiB / 52.7% CPU)}	🥇 51831 _{(100 MiB / 52.7% CPU)}	14574 _{(137 MiB / 24.2% CPU)}	14876 _{(137 MiB / 24.2% CPU)}	45383 _{(93 MiB / 49.8% CPU)}	45383 _{(93 MiB / 49.8% CPU)}
HTTP/2 · TLS	HTTP/1 · TLS	🥇 45126 _{(102 MiB / 51.7% CPU)}	🥇 45126 _{(102 MiB / 51.7% CPU)}	Not possible	Not possible	39564 _{(95 MiB / 51.6% CPU)}	39564 _{(95 MiB / 51.6% CPU)}
HTTP/2 · TLS	HTTP/2 · plain	🥇 110147 _{(90 MiB / 36.2% CPU)}	🥇 110147 _{(90 MiB / 36.2% CPU)}	Not possible	Not possible	75865 _{(101 MiB / 52.3% CPU)}	75865 _{(101 MiB / 52.3% CPU)}
HTTP/2 · TLS	HTTP/2 · TLS	🥇 97618 _{(87 MiB / 37.5% CPU)}	🥇 97618 _{(87 MiB / 37.5% CPU)}	Not possible	Not possible	69005 _{(101 MiB / 49.6% CPU)}	69005 _{(101 MiB / 49.6% CPU)}
HTTP/2 · TLS	HTTP/3 · QUIC	🥇 40752 _{(141 MiB / 52.8% CPU)}	🥇 40752 _{(141 MiB / 52.8% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	36652 _{(132 MiB / 53.1% CPU)}	36652 _{(132 MiB / 53.1% CPU)}
HTTP/3 · QUIC	HTTP/1 · plain	🥇 24291 _{(112 MiB / 44.5% CPU)}	🥇 24291 _{(112 MiB / 44.5% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	22638 _{(121 MiB / 48.1% CPU)}	23401 _{(121 MiB / 48.1% CPU)}
HTTP/3 · QUIC	HTTP/1 · TLS	🥇 22674 _{(119 MiB / 44.6% CPU)}	🥇 22674 _{(119 MiB / 44.6% CPU)}	Not possible	Not possible	20885 _{(119 MiB / 49.9% CPU)}	21058 _{(119 MiB / 49.9% CPU)}
HTTP/3 · QUIC	HTTP/2 · plain	🥇 37142 _{(129 MiB / 49.4% CPU)}	🥇 37142 _{(129 MiB / 49.4% CPU)}	Not possible (no H3→H2)	Not possible (no H3→H2)	34757 _{(155 MiB / 50.2% CPU)}	34757 _{(155 MiB / 50.2% CPU)}
HTTP/3 · QUIC	HTTP/2 · TLS	🥇 33873 _{(130 MiB / 47.9% CPU)}	🥇 33873 _{(130 MiB / 47.9% CPU)}	Not possible (no H3→H2)	Not possible (no H3→H2)	33573 _{(163 MiB / 48.2% CPU)}	33573 _{(163 MiB / 48.2% CPU)}
HTTP/3 · QUIC	HTTP/3 · QUIC	20878 _{(129 MiB / 46.4% CPU)}	20878 _{(129 MiB / 46.4% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	🥇 24536 _{(173 MiB / 50.8% CPU)}	🥇 24536 _{(173 MiB / 50.8% CPU)}

MITM (TWP only)

Same Client×Origin wires with interception on (compare-product 32960766249). Lite = no-op handlers (unchanged-lite finish). Full = mutating handlers (x-twp-rps-probe) forcing non-lite re-encode. nginx/YARP cannot MITM. Lite÷Reverse / Full÷Reverse vs bare reverse (same job).

Post-fix note (2026-08-26): Phase 2 closed the H3→H1 Full gap: preencoded QPACK relay was gated on empty ViaHeaderPseudonym while the default is "titanium-web-proxy". Cool paired laptop gates (h3h1-spot/, c=64): H3→H1 plain Full÷Reverse 0.91×, H3→H1 TLS 0.995×, H1 plain 0.91× — all ≥0.80. Published table below is still pre-fix CI; remasure via GHA compare-product ×3 is pending.

Client	Origin	Lite sustain	Full sustain	Lite÷Reverse	Full÷Reverse
HTTP/1 · plain	HTTP/1 · plain	🥇 40598 _{(76 MiB / 48.1% CPU)}	35091 _{(79 MiB / 52.6% CPU)}	0.99×	0.86×
HTTP/1 · plain	HTTP/1 · TLS	🥇 34487 _{(88 MiB / 49.2% CPU)}	30702 _{(91 MiB / 51.3% CPU)}	0.99×	0.88×
HTTP/1 · plain	HTTP/2 · plain	🥇 53742 _{(120 MiB / 50.9% CPU)}	52732 _{(123 MiB / 50.6% CPU)}	0.97×	0.95×
HTTP/1 · plain	HTTP/2 · TLS	🥇 47896 _{(115 MiB / 51.6% CPU)}	48004 _{(117 MiB / 49.7% CPU)}	0.97×	0.97×
HTTP/1 · plain	HTTP/3 · QUIC	🥇 27577 _{(109 MiB / 52.6% CPU)}	27356 _{(112 MiB / 51.4% CPU)}	0.99×	0.98×
HTTP/1 · TLS	HTTP/1 · plain	🥇 33374 _{(87 MiB / 49.9% CPU)}	29388 _{(87 MiB / 48.4% CPU)}	0.98×	0.86×
HTTP/1 · TLS	HTTP/1 · TLS	🥇 30543 _{(91 MiB / 46.3% CPU)}	27441 _{(90 MiB / 52.5% CPU)}	0.98×	0.88×
HTTP/1 · TLS	HTTP/2 · plain	🥇 41828 _{(126 MiB / 50.7% CPU)}	41796 _{(136 MiB / 48.7% CPU)}	0.96×	0.95×
HTTP/1 · TLS	HTTP/2 · TLS	🥇 39553 _{(120 MiB / 49.9% CPU)}	38882 _{(125 MiB / 51.0% CPU)}	0.99×	0.97×
HTTP/1 · TLS	HTTP/3 · QUIC	🥇 24173 _{(109 MiB / 52.1% CPU)}	23744 _{(111 MiB / 51.9% CPU)}	1.00×	0.98×
HTTP/2 · plain	HTTP/1 · plain	🥇 52800 _{(97 MiB / 52.0% CPU)}	51344 _{(94 MiB / 53.0% CPU)}	0.98×	0.95×
HTTP/2 · plain	HTTP/1 · TLS	🥇 44671 _{(107 MiB / 54.1% CPU)}	44315 _{(103 MiB / 54.3% CPU)}	0.96×	0.95×
HTTP/2 · plain	HTTP/2 · plain	🥇 101312 _{(71 MiB / 49.5% CPU)}	18755 _{(70 MiB / 51.0% CPU)}	0.85×	0.16×
HTTP/2 · plain	HTTP/2 · TLS	🥇 88479 _{(89 MiB / 48.2% CPU)}	13680 _{(79 MiB / 48.5% CPU)}	0.87×	0.13×
HTTP/2 · plain	HTTP/3 · QUIC	🥇 41372 _{(132 MiB / 55.0% CPU)}	40516 _{(129 MiB / 53.9% CPU)}	0.98×	0.96×
HTTP/2 · TLS	HTTP/1 · plain	🥇 49960 _{(107 MiB / 50.6% CPU)}	49168 _{(108 MiB / 52.2% CPU)}	0.96×	0.95×
HTTP/2 · TLS	HTTP/1 · TLS	🥇 42231 _{(102 MiB / 52.5% CPU)}	43365 _{(99 MiB / 53.1% CPU)}	0.94×	0.96×
HTTP/2 · TLS	HTTP/2 · plain	🥇 96587 _{(98 MiB / 46.7% CPU)}	19466 _{(87 MiB / 53.9% CPU)}	0.88×	0.18×
HTTP/2 · TLS	HTTP/2 · TLS	🥇 85710 _{(96 MiB / 43.5% CPU)}	14442 _{(91 MiB / 49.4% CPU)}	0.88×	0.15×
HTTP/2 · TLS	HTTP/3 · QUIC	🥇 39904 _{(138 MiB / 53.5% CPU)}	39272 _{(139 MiB / 54.9% CPU)}	0.98×	0.96×
HTTP/3 · QUIC	HTTP/1 · plain	🥇 23440 _{(111 MiB / 45.6% CPU)}	16283 _{(111 MiB / 49.0% CPU)}	0.96×	0.67×
HTTP/3 · QUIC	HTTP/1 · TLS	🥇 20759 _{(120 MiB / 46.9% CPU)}	13849 _{(99 MiB / 49.8% CPU)}	0.92×	0.61×
HTTP/3 · QUIC	HTTP/2 · plain	🥇 33821 _{(138 MiB / 49.2% CPU)}	32620 _{(140 MiB / 49.6% CPU)}	0.91×	0.88×
HTTP/3 · QUIC	HTTP/2 · TLS	🥇 31759 _{(141 MiB / 50.2% CPU)}	31318 _{(145 MiB / 51.1% CPU)}	0.94×	0.92×
HTTP/3 · QUIC	HTTP/3 · QUIC	🥇 19614 _{(126 MiB / 48.9% CPU)}	18634 _{(111 MiB / 45.7% CPU)}	0.94×	0.89×
HTTP/1 · plain (CONNECT)	HTTP/1 · TLS	🥇 25522 _{(106 MiB / 53.6% CPU)}	24557 _{(103 MiB / 55.8% CPU)}	n/a	n/a

Linux — Titanium vs nginx vs YARP

Reverse

Median of 3 repeats on ubuntu-latest (4 vCPU / 16 GiB). Bare reverse 5×5 @ c71937a2 — compare-product 32960766249. Warmup 2s / measure 8s; concurrency 8, 16, 32, 64. Linux nginx is the authoritative nginx baseline. nginx terminate peers use keepalive 256 + streaming buffers. The RPS workflow installs nginx.org mainline (http_v3_module) and libmsquic. Prefer ratios over absolute RPS.

Client	Origin	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
HTTP/1 · plain	HTTP/1 · plain	32442 _{(82 MiB / 50.0% CPU)}	32442 _{(82 MiB / 50.0% CPU)}	🥇 38910 _{(72 MiB / 40.5% CPU)}	🥇 38910 _{(72 MiB / 40.5% CPU)}	27468 _{(115 MiB / 49.9% CPU)}	27468 _{(115 MiB / 49.9% CPU)}
HTTP/1 · plain	HTTP/1 · TLS	🥇 24088 _{(99 MiB / 50.0% CPU)}	🥇 24088 _{(99 MiB / 50.0% CPU)}	Not possible	Not possible	21483 _{(124 MiB / 50.4% CPU)}	21483 _{(124 MiB / 50.4% CPU)}
HTTP/1 · plain	HTTP/2 · plain	🥇 38601 _{(129 MiB / 51.5% CPU)}	🥇 38601 _{(129 MiB / 51.5% CPU)}	Not possible	Not possible	34502 _{(125 MiB / 49.5% CPU)}	34502 _{(125 MiB / 49.5% CPU)}
HTTP/1 · plain	HTTP/2 · TLS	🥇 31103 _{(131 MiB / 49.8% CPU)}	🥇 31103 _{(131 MiB / 49.8% CPU)}	Not possible	Not possible	29700 _{(132 MiB / 48.1% CPU)}	29700 _{(132 MiB / 48.1% CPU)}
HTTP/1 · plain	HTTP/3 · QUIC	🥇 22339 _{(131 MiB / 51.9% CPU)}	🥇 22339 _{(131 MiB / 51.9% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	21210 _{(149 MiB / 49.3% CPU)}	21210 _{(149 MiB / 49.3% CPU)}
HTTP/1 · TLS	HTTP/1 · plain	23293 _{(105 MiB / 49.3% CPU)}	23293 _{(105 MiB / 49.3% CPU)}	🥇 26873 _{(97 MiB / 41.5% CPU)}	🥇 26873 _{(97 MiB / 41.5% CPU)}	19966 _{(136 MiB / 50.1% CPU)}	19966 _{(136 MiB / 50.1% CPU)}
HTTP/1 · TLS	HTTP/1 · TLS	🥇 19135 _{(104 MiB / 48.3% CPU)}	🥇 19135 _{(104 MiB / 48.3% CPU)}	Not possible	Not possible	17065 _{(138 MiB / 49.6% CPU)}	17065 _{(138 MiB / 49.6% CPU)}
HTTP/1 · TLS	HTTP/2 · plain	🥇 26310 _{(142 MiB / 49.8% CPU)}	🥇 26310 _{(142 MiB / 49.8% CPU)}	Not possible	Not possible	24764 _{(144 MiB / 49.1% CPU)}	24764 _{(144 MiB / 49.1% CPU)}
HTTP/1 · TLS	HTTP/2 · TLS	🥇 23637 _{(146 MiB / 48.0% CPU)}	🥇 23637 _{(146 MiB / 48.0% CPU)}	Not possible	Not possible	22212 _{(145 MiB / 47.2% CPU)}	22212 _{(145 MiB / 47.2% CPU)}
HTTP/1 · TLS	HTTP/3 · QUIC	🥇 17278 _{(134 MiB / 51.3% CPU)}	🥇 17278 _{(134 MiB / 51.3% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	16348 _{(157 MiB / 49.5% CPU)}	16348 _{(157 MiB / 49.5% CPU)}
HTTP/2 · plain	HTTP/1 · plain	🥇 37017 _{(111 MiB / 53.0% CPU)}	🥇 37017 _{(111 MiB / 53.0% CPU)}	Not possible	Not possible	34334 _{(118 MiB / 49.9% CPU)}	34334 _{(118 MiB / 49.9% CPU)}
HTTP/2 · plain	HTTP/1 · TLS	🥇 28470 _{(126 MiB / 51.8% CPU)}	🥇 28470 _{(126 MiB / 51.8% CPU)}	Not possible	Not possible	25800 _{(124 MiB / 50.2% CPU)}	25800 _{(124 MiB / 50.2% CPU)}
HTTP/2 · plain	HTTP/2 · plain	🥇 64814 _{(100 MiB / 39.7% CPU)}	🥇 64814 _{(100 MiB / 39.7% CPU)}	Not possible	Not possible	48617 _{(121 MiB / 46.6% CPU)}	48617 _{(121 MiB / 46.6% CPU)}
HTTP/2 · plain	HTTP/2 · TLS	🥇 51516 _{(109 MiB / 39.4% CPU)}	🥇 51516 _{(109 MiB / 39.4% CPU)}	Not possible	Not possible	39280 _{(124 MiB / 45.8% CPU)}	39280 _{(124 MiB / 45.8% CPU)}
HTTP/2 · plain	HTTP/3 · QUIC	🥇 26375 _{(140 MiB / 50.0% CPU)}	🥇 26375 _{(140 MiB / 50.0% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	25387 _{(154 MiB / 46.5% CPU)}	25387 _{(154 MiB / 46.5% CPU)}
HTTP/2 · TLS	HTTP/1 · plain	🥇 34630 _{(118 MiB / 52.0% CPU)}	🥇 34630 _{(118 MiB / 52.0% CPU)}	14998 _{(97 MiB / 19.4% CPU)}	14998 _{(97 MiB / 19.4% CPU)}	29299 _{(121 MiB / 49.6% CPU)}	29299 _{(121 MiB / 49.6% CPU)}
HTTP/2 · TLS	HTTP/1 · TLS	🥇 26593 _{(115 MiB / 50.4% CPU)}	🥇 26593 _{(115 MiB / 50.4% CPU)}	Not possible	Not possible	23102 _{(128 MiB / 49.8% CPU)}	23102 _{(128 MiB / 49.8% CPU)}
HTTP/2 · TLS	HTTP/2 · plain	🥇 57728 _{(112 MiB / 39.3% CPU)}	🥇 57728 _{(112 MiB / 39.3% CPU)}	Not possible	Not possible	39242 _{(127 MiB / 46.9% CPU)}	39242 _{(127 MiB / 46.9% CPU)}
HTTP/2 · TLS	HTTP/2 · TLS	🥇 48512 _{(115 MiB / 38.9% CPU)}	🥇 48512 _{(115 MiB / 38.9% CPU)}	Not possible	Not possible	33817 _{(128 MiB / 45.9% CPU)}	33817 _{(128 MiB / 45.9% CPU)}
HTTP/2 · TLS	HTTP/3 · QUIC	🥇 25113 _{(146 MiB / 49.1% CPU)}	🥇 25113 _{(146 MiB / 49.1% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	22435 _{(156 MiB / 46.5% CPU)}	22435 _{(156 MiB / 46.5% CPU)}
HTTP/3 · QUIC	HTTP/1 · plain	🥇 20531 _{(143 MiB / 49.8% CPU)}	🥇 20531 _{(143 MiB / 49.8% CPU)}	12370 _{(102 MiB / 22.6% CPU)}	15142 _{(102 MiB / 22.6% CPU)}	18328 _{(179 MiB / 50.1% CPU)}	18328 _{(179 MiB / 50.1% CPU)}
HTTP/3 · QUIC	HTTP/1 · TLS	🥇 15566 _{(147 MiB / 47.3% CPU)}	🥇 15566 _{(147 MiB / 47.3% CPU)}	Not possible	Not possible	14627 _{(194 MiB / 50.6% CPU)}	14627 _{(194 MiB / 50.6% CPU)}
HTTP/3 · QUIC	HTTP/2 · plain	🥇 26473 _{(139 MiB / 53.1% CPU)}	🥇 26473 _{(139 MiB / 53.1% CPU)}	Not possible (no H3→H2)	Not possible (no H3→H2)	23598 _{(195 MiB / 48.3% CPU)}	23598 _{(195 MiB / 48.3% CPU)}
HTTP/3 · QUIC	HTTP/2 · TLS	🥇 23194 _{(147 MiB / 51.4% CPU)}	🥇 23194 _{(147 MiB / 51.4% CPU)}	Not possible (no H3→H2)	Not possible (no H3→H2)	21588 _{(190 MiB / 47.7% CPU)}	21588 _{(190 MiB / 47.7% CPU)}
HTTP/3 · QUIC	HTTP/3 · QUIC	🥇 18908 _{(149 MiB / 46.9% CPU)}	🥇 18908 _{(149 MiB / 46.9% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	15495 _{(192 MiB / 48.1% CPU)}	15495 _{(192 MiB / 48.1% CPU)}

MITM (TWP only)

Same Client×Origin wires with interception on (compare-product 32960766249). Lite = no-op handlers (unchanged-lite finish). Full = mutating handlers (x-twp-rps-probe) forcing non-lite re-encode. nginx/YARP cannot MITM. Lite÷Reverse / Full÷Reverse vs bare reverse (same job).

Post-fix note (2026-08-26): Phase 2 closed the H3→H1 Full gap: preencoded QPACK relay was gated on empty ViaHeaderPseudonym while the default is "titanium-web-proxy". Cool paired laptop gates (h3h1-spot/, c=64): H3→H1 plain Full÷Reverse 0.91×, H3→H1 TLS 0.995×, H1 plain 0.91× — all ≥0.80. Published table below is still pre-fix CI; remasure via GHA compare-product ×3 is pending.

Client	Origin	Lite sustain	Full sustain	Lite÷Reverse	Full÷Reverse
HTTP/1 · plain	HTTP/1 · plain	🥇 31341 _{(84 MiB / 50.5% CPU)}	25750 _{(95 MiB / 50.7% CPU)}	0.97×	0.79×
HTTP/1 · plain	HTTP/1 · TLS	🥇 24143 _{(107 MiB / 51.3% CPU)}	19549 _{(114 MiB / 51.0% CPU)}	1.00×	0.81×
HTTP/1 · plain	HTTP/2 · plain	🥇 38706 _{(135 MiB / 53.0% CPU)}	36217 _{(140 MiB / 52.6% CPU)}	1.00×	0.94×
HTTP/1 · plain	HTTP/2 · TLS	🥇 30144 _{(147 MiB / 51.5% CPU)}	29575 _{(141 MiB / 51.1% CPU)}	0.97×	0.95×
HTTP/1 · plain	HTTP/3 · QUIC	🥇 21802 _{(134 MiB / 53.1% CPU)}	22335 _{(132 MiB / 52.9% CPU)}	0.98×	1.00×
HTTP/1 · TLS	HTTP/1 · plain	🥇 22828 _{(110 MiB / 50.5% CPU)}	18135 _{(111 MiB / 50.8% CPU)}	0.98×	0.78×
HTTP/1 · TLS	HTTP/1 · TLS	🥇 19298 _{(109 MiB / 49.2% CPU)}	15947 _{(120 MiB / 49.6% CPU)}	1.01×	0.83×
HTTP/1 · TLS	HTTP/2 · plain	🥇 26264 _{(152 MiB / 50.6% CPU)}	25256 _{(165 MiB / 51.2% CPU)}	1.00×	0.96×
HTTP/1 · TLS	HTTP/2 · TLS	🥇 22284 _{(157 MiB / 49.5% CPU)}	22285 _{(153 MiB / 49.6% CPU)}	0.94×	0.94×
HTTP/1 · TLS	HTTP/3 · QUIC	🥇 17158 _{(154 MiB / 51.9% CPU)}	16953 _{(149 MiB / 51.7% CPU)}	0.99×	0.98×
HTTP/2 · plain	HTTP/1 · plain	🥇 35954 _{(111 MiB / 53.8% CPU)}	35149 _{(114 MiB / 53.9% CPU)}	0.97×	0.95×
HTTP/2 · plain	HTTP/1 · TLS	🥇 27724 _{(122 MiB / 52.6% CPU)}	26872 _{(123 MiB / 52.4% CPU)}	0.97×	0.94×
HTTP/2 · plain	HTTP/2 · plain	🥇 57129 _{(101 MiB / 48.2% CPU)}	14442 _{(96 MiB / 51.5% CPU)}	0.88×	0.22×
HTTP/2 · plain	HTTP/2 · TLS	🥇 45119 _{(99 MiB / 45.6% CPU)}	9618 _{(98 MiB / 49.4% CPU)}	0.88×	0.19×
HTTP/2 · plain	HTTP/3 · QUIC	🥇 26558 _{(136 MiB / 50.2% CPU)}	26568 _{(140 MiB / 51.2% CPU)}	1.01×	1.01×
HTTP/2 · TLS	HTTP/1 · plain	🥇 32900 _{(120 MiB / 53.4% CPU)}	33051 _{(121 MiB / 53.2% CPU)}	0.95×	0.95×
HTTP/2 · TLS	HTTP/1 · TLS	🥇 25456 _{(116 MiB / 51.0% CPU)}	25225 _{(123 MiB / 50.7% CPU)}	0.96×	0.95×
HTTP/2 · TLS	HTTP/2 · plain	🥇 50915 _{(110 MiB / 46.8% CPU)}	13907 _{(108 MiB / 49.9% CPU)}	0.88×	0.24×
HTTP/2 · TLS	HTTP/2 · TLS	🥇 42013 _{(109 MiB / 44.5% CPU)}	9756 _{(108 MiB / 48.7% CPU)}	0.87×	0.20×
HTTP/2 · TLS	HTTP/3 · QUIC	🥇 24834 _{(139 MiB / 49.7% CPU)}	24670 _{(152 MiB / 50.8% CPU)}	0.99×	0.98×
HTTP/3 · QUIC	HTTP/1 · plain	🥇 19193 _{(138 MiB / 50.6% CPU)}	13232 _{(136 MiB / 48.4% CPU)}	0.93×	0.64×
HTTP/3 · QUIC	HTTP/1 · TLS	🥇 15251 _{(158 MiB / 48.7% CPU)}	9627 _{(153 MiB / 47.0% CPU)}	0.98×	0.62×
HTTP/3 · QUIC	HTTP/2 · plain	🥇 24530 _{(152 MiB / 55.6% CPU)}	24462 _{(158 MiB / 55.7% CPU)}	0.93×	0.92×
HTTP/3 · QUIC	HTTP/2 · TLS	🥇 21297 _{(157 MiB / 53.4% CPU)}	21013 _{(154 MiB / 54.0% CPU)}	0.92×	0.91×
HTTP/3 · QUIC	HTTP/3 · QUIC	🥇 16680 _{(147 MiB / 48.6% CPU)}	16729 _{(154 MiB / 48.0% CPU)}	0.88×	0.88×
HTTP/1 · plain (CONNECT)	HTTP/1 · TLS	🥇 14398 _{(118 MiB / 52.1% CPU)}	14522 _{(135 MiB / 51.5% CPU)}	n/a	n/a

Tiny JSON reverse is nginx’s best case on Linux

The tables above use ~64 B keep-alive GET on loopback. On Linux H1 reverse, nginx leads; YARP sits near TWP. Heavier bodies, POSTs, TLS handshake cost, and lossy/HOL workloads (below) change the picture. MITM rows remain TWP-only. nginx HTTP/3 is inbound-terminate only (see note above).

Why isn’t HTTP/3 > HTTP/2 > HTTP/1 in raw RPS?

For tiny JSON responses (~64 B) on loopback, that ordering is not expected: topology (TLS hop count, terminate vs MITM) dominates; HTTP/2 and HTTP/3 help multiplexing, not single-origin tiny-GET RPS. See the lossy tables below for a workload where protocol design matters.

Heavier reverse workloads

Separate from the tiny-GET matrix. Same measurement environments. Modes: compare-bodies, compare-post, compare-lossy, compare-tls-cost, compare-arch in RpsLoadProbe. PUT with the same body is the same proxy work as POST; DELETE with no body matches GET — only POST is published. Bodies/POST/lossy stay half-duplex. compare-arch is the slow-consumer / early-response / duplex set. Laptop numbers are on Performance Local Lab; CI medians go in the tables below.

Lossy link = userspace shim (not kernel netem): TCP gets per-buffer delay + occasional whole-connection stalls (honest HOL for multiplexed H2); UDP gets per-datagram delay + drops (QUIC). compare-lossy publishes H1/H2/H3; H3 is where the protocol design is supposed to matter.

Windows — heavier reverse GET (64 KiB / 256 KiB)

Median of 3 repeats on windows-latest @ 9d7c2966. Source: Actions 32871900682 (compare-bodies). Warmup 2s / measure 8s. RPS cells include (MiB / CPU%) footprints.

Body	Client	Origin	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
64 KiB	HTTP/1 · TLS	HTTP/1 · plain	🥇 10,297 _{(99 MiB / 45.5% CPU)}	10,564 _{(99 MiB / 45.5% CPU)}	717 _{(137 MiB / 24.6% CPU)}	739 _{(137 MiB / 24.6% CPU)}	9,283 _{(110 MiB / 44.7% CPU)}	9,413 _{(110 MiB / 44.7% CPU)}
64 KiB	HTTP/2 · TLS	HTTP/1 · plain	🥇 9,135 _{(168 MiB / 46.2% CPU)}	9,135 _{(168 MiB / 46.2% CPU)}	626 _{(137 MiB / 24.8% CPU)}	637 _{(137 MiB / 24.8% CPU)}	7,533 _{(108 MiB / 49.7% CPU)}	7,745 _{(108 MiB / 49.7% CPU)}
64 KiB	HTTP/3 · QUIC	HTTP/1 · plain	🥇 4,728 _{(108 MiB / 39.8% CPU)}	4,900 _{(108 MiB / 39.8% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	3,995 _{(177 MiB / 49.0% CPU)}	4,035 _{(177 MiB / 49.0% CPU)}
256 KiB	HTTP/1 · TLS	HTTP/1 · plain	🥇 3,056 _{(88 MiB / 42.6% CPU)}	3,271 _{(88 MiB / 42.6% CPU)}	191 _{(136 MiB / 24.8% CPU)}	194 _{(136 MiB / 24.8% CPU)}	2,488 _{(115 MiB / 45.7% CPU)}	2,839 _{(115 MiB / 45.7% CPU)}
256 KiB	HTTP/2 · TLS	HTTP/1 · plain	🥇 2,568 _{(115 MiB / 38.9% CPU)}	2,639 _{(115 MiB / 38.9% CPU)}	163 _{(137 MiB / 24.9% CPU)}	163 _{(137 MiB / 24.9% CPU)}	2,003 _{(132 MiB / 41.6% CPU)}	2,003 _{(132 MiB / 41.6% CPU)}
256 KiB	HTTP/3 · QUIC	HTTP/1 · plain	🥇 1,210 _{(88 MiB / 39.3% CPU)}	1,254 _{(88 MiB / 39.3% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	1,100 _{(125 MiB / 43.9% CPU)}	1,136 _{(125 MiB / 43.9% CPU)}

nginx/Windows collapses on large reverse bodies in this harness; treat as same-OS only. H1 TLS 64 KiB ≈ 1.11× YARP; 256 KiB ≈ 1.23×. H2→H1 64 KiB ≈ 1.21×; H3→H1 64 KiB ≈ 1.18×.

Linux — heavier reverse GET (64 KiB / 256 KiB)

Median of 3 repeats @ 9d7c2966. Source: Actions 32871900682 (compare-bodies). Warmup 2s / measure 8s.

Body	Client	Origin	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
64 KiB	HTTP/1 · TLS	HTTP/1 · plain	🥇 7,902 _{(170 MiB / 44.4% CPU)}	7,902 _{(170 MiB / 44.4% CPU)}	5,518 _{(96 MiB / 52.5% CPU)}	5,518 _{(96 MiB / 52.5% CPU)}	6,420 _{(158 MiB / 48.8% CPU)}	6,420 _{(158 MiB / 48.8% CPU)}
64 KiB	HTTP/2 · TLS	HTTP/1 · plain	🥇 5,831 _{(218 MiB / 38.9% CPU)}	5,831 _{(218 MiB / 38.9% CPU)}	1,790 _{(95 MiB / 23.6% CPU)}	1,925 _{(95 MiB / 23.6% CPU)}	4,739 _{(161 MiB / 45.9% CPU)}	4,739 _{(161 MiB / 45.9% CPU)}
64 KiB	HTTP/3 · QUIC	HTTP/1 · plain	🥇 5,384 _{(177 MiB / 44.5% CPU)}	5,384 _{(177 MiB / 44.5% CPU)}	1,614 _{(113 MiB / 22.0% CPU)}	1,718 _{(113 MiB / 22.0% CPU)}	4,236 _{(219 MiB / 51.1% CPU)}	4,236 _{(219 MiB / 51.1% CPU)}
256 KiB	HTTP/1 · TLS	HTTP/1 · plain	🥇 2,742 _{(121 MiB / 37.2% CPU)}	2,742 _{(121 MiB / 37.2% CPU)}	1,732 _{(95 MiB / 53.3% CPU)}	1,732 _{(95 MiB / 53.3% CPU)}	2,142 _{(171 MiB / 45.9% CPU)}	2,142 _{(171 MiB / 45.9% CPU)}
256 KiB	HTTP/2 · TLS	HTTP/1 · plain	🥇 1,535 _{(206 MiB / 32.7% CPU)}	1,535 _{(206 MiB / 32.7% CPU)}	538 _{(96 MiB / 18.6% CPU)}	538 _{(96 MiB / 18.6% CPU)}	1,319 _{(164 MiB / 42.7% CPU)}	1,330 _{(164 MiB / 42.7% CPU)}
256 KiB	HTTP/3 · QUIC	HTTP/1 · plain	🥇 1,432 _{(148 MiB / 43.1% CPU)}	1,432 _{(148 MiB / 43.1% CPU)}	448 _{(107 MiB / 23.3% CPU)}	448 _{(107 MiB / 23.3% CPU)}	1,270 _{(218 MiB / 47.4% CPU)}	1,270 _{(218 MiB / 47.4% CPU)}

On this GHA pass TWP÷YARP H1 TLS ≈ 1.23× (64 KiB) / 1.28× (256 KiB); H2→H1 ≈ 1.23× / 1.16×; H3→H1 ≈ 1.27× / 1.13×. TWP÷nginx H1 TLS ≈ 1.43 / 1.58. Absolute RPS swings by VM; prefer ratios.

Windows — POST 64 KiB request + 64 KiB response

Median of 3 repeats on windows-latest @ 9d7c2966. Source: Actions 32866714851 (compare-post).

Client	Origin	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
HTTP/1 · TLS	HTTP/1 · plain	🥇 8,612 _{(84 MiB / 42.0% CPU)}	9,133 _{(84 MiB / 42.0% CPU)}	497 _{(138 MiB / 24.8% CPU)}	538 _{(138 MiB / 24.8% CPU)}	5,837 _{(96 MiB / 56.0% CPU)}	6,283 _{(96 MiB / 56.0% CPU)}
HTTP/2 · TLS	HTTP/1 · plain	🥇 6,241 _{(196 MiB / 49.7% CPU)}	6,242 _{(196 MiB / 49.7% CPU)}	486 _{(139 MiB / 24.9% CPU)}	493 _{(139 MiB / 24.9% CPU)}	5,106 _{(118 MiB / 50.9% CPU)}	5,147 _{(118 MiB / 50.9% CPU)}
HTTP/3 · QUIC	HTTP/1 · plain	🥇 2,691 _{(118 MiB / 43.7% CPU)}	2,937 _{(118 MiB / 43.7% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	2,549 _{(132 MiB / 49.5% CPU)}	2,747 _{(132 MiB / 49.5% CPU)}

TWP leads H1 POST (1.5× YARP), H2 POST (1.2× YARP), and H3 POST (~1.1× YARP).

Linux — POST 64 KiB request + 64 KiB response

Median of 3 repeats @ 9d7c2966. Source: Actions 32866714851 (compare-post).

Client	Origin	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
HTTP/1 · TLS	HTTP/1 · plain	🥇 6,746 _{(127 MiB / 41.8% CPU)}	6,746 _{(127 MiB / 41.8% CPU)}	5,443 _{(98 MiB / 44.8% CPU)}	5,443 _{(98 MiB / 44.8% CPU)}	4,410 _{(176 MiB / 53.8% CPU)}	4,410 _{(176 MiB / 53.8% CPU)}
HTTP/2 · TLS	HTTP/1 · plain	🥇 4,720 _{(220 MiB / 47.0% CPU)}	4,720 _{(220 MiB / 47.0% CPU)}	2,362 _{(106 MiB / 21.8% CPU)}	2,475 _{(106 MiB / 21.8% CPU)}	3,616 _{(144 MiB / 48.3% CPU)}	3,626 _{(144 MiB / 48.3% CPU)}
HTTP/3 · QUIC	HTTP/1 · plain	🥇 3,306 _{(223 MiB / 43.7% CPU)}	3,306 _{(223 MiB / 43.7% CPU)}	835 _{(111 MiB / 24.6% CPU)}	835 _{(111 MiB / 24.6% CPU)}	2,959 _{(260 MiB / 51.5% CPU)}	2,959 _{(260 MiB / 51.5% CPU)}

Linux nginx H1/H2/H3 POST completed (nginx.org mainline). TWP÷YARP H1 ≈ 1.5×; H2 ≈ 1.3×; H3 ≈ 1.1×. TWP÷nginx H3 ≈ 4×.

Windows — lossy / high-RTT (H2 HOL / H3 loss)

Userspace 5 ms one-way delay + 1% TCP connection stall (H1/H2) or UDP datagram drop (H3); 64 KiB GET. H1/H2: median of 3 repeats on windows-latest @ 9d7c2966 — 32866717729 (compare-lossy). H3: GHA Windows userspace UDP shim collapses (sustain 0); published H3 row is the laptop quic-http3 remasure under the same delay/loss workload (Performance Local Lab, `windows-20260822-lossy-h3-quic/).

Client	Origin	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
HTTP/1 · TLS	HTTP/1 · plain	🥇 663 _{(98 MiB / 4.8% CPU)}	663 _{(98 MiB / 4.8% CPU)}	634 _{(137 MiB / 19.6% CPU)}	634 _{(137 MiB / 19.6% CPU)}	662 _{(113 MiB / 5.7% CPU)}	662 _{(113 MiB / 5.7% CPU)}
HTTP/2 · TLS	HTTP/1 · plain	🥇 59 _{(122 MiB / 1.7% CPU)}	88 _{(122 MiB / 1.7% CPU)}	18 _{(137 MiB / 0.5% CPU)}	18 _{(137 MiB / 0.5% CPU)}	18 _{(84 MiB / 1.1% CPU)}	18 _{(84 MiB / 1.1% CPU)}
HTTP/3 · QUIC	HTTP/1 · plain	🥇 1,572	1,572	Not possible (no QUIC)	Not possible	0	50

TWP H2 HOL leads (~3.31× YARP). H3 is the protocol-shape win vs H2 HOL on the same lossy session; Win H3 GHA remains 0 (laptop remasure kept above).

Linux — lossy / high-RTT (H2 HOL / H3 loss)

Median of 3 repeats @ 9d7c2966. Source: 32866717729 (compare-lossy; lossy H3 uses quic-http3).

Client	Origin	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
HTTP/1 · TLS	HTTP/1 · plain	1,201 _{(142 MiB / 12.9% CPU)}	1,201 _{(142 MiB / 12.9% CPU)}	🥇 1,206 _{(97 MiB / 11.8% CPU)}	1,206 _{(97 MiB / 11.8% CPU)}	1,197 _{(144 MiB / 16.6% CPU)}	1,197 _{(144 MiB / 16.6% CPU)}
HTTP/2 · TLS	HTTP/1 · plain	🥇 309 _{(191 MiB / 6.5% CPU)}	309 _{(191 MiB / 6.5% CPU)}	40 _{(95 MiB / 0.3% CPU)}	42 _{(95 MiB / 0.3% CPU)}	40 _{(118 MiB / 1.4% CPU)}	44 _{(118 MiB / 1.4% CPU)}
HTTP/3 · QUIC	HTTP/1 · plain	🥇 332 _{(149 MiB / 13.3% CPU)}	332 _{(149 MiB / 13.3% CPU)}	88 _{(105 MiB / 2.7% CPU)}	88 _{(105 MiB / 2.7% CPU)}	330 _{(176 MiB / 17.9% CPU)}	330 _{(176 MiB / 17.9% CPU)}

TWP H2 HOL ≫ YARP (~7.7×). H3 TWP÷YARP ≈ 1×.

Architecture-sensitive

compare-arch isolates slow app readers, origin-early response, H2 duplex, and WebSocket echo. See TWP vs YARP IO model. Laptop 1-rep numbers are on Performance Local Lab.

Median of 3 repeats on matched 4 vCPU / 16 GiB runners @ 9d7c2966 (32866720742) (compare-arch). Slow consumer = 256 KiB GET, 16 KiB read + 8 ms sleep. Early response = 64 KiB POST, origin writes after 8 KiB. Duplex H2 = overlapping 64 KiB POST on H2 TLS↔H2 TLS. WebSocket = echo round-trips/sec.

compare-lossy (slow network) is already published above; it is not a slow app reader.

Windows

Scenario	Client	Origin	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
Slow consumer (256 KiB GET, throttled client read)	HTTP/1 · TLS	HTTP/1 · plain	🥇 248 _{(91 MiB / 3.8% CPU)}	248 _{(91 MiB / 3.8% CPU)}	209 _{(140 MiB / 24.7% CPU)}	209 _{(140 MiB / 24.7% CPU)}	248 _{(110 MiB / 4.9% CPU)}	248 _{(110 MiB / 4.9% CPU)}
Slow consumer (256 KiB GET, throttled client read)	HTTP/2 · TLS	HTTP/1 · plain	248 _{(125 MiB / 3.8% CPU)}	248 _{(125 MiB / 3.8% CPU)}	166 _{(137 MiB / 24.6% CPU)}	166 _{(137 MiB / 24.6% CPU)}	🥇 249 _{(112 MiB / 7.4% CPU)}	249 _{(112 MiB / 7.4% CPU)}
Slow consumer (256 KiB GET, throttled client read)	HTTP/3 · QUIC	HTTP/1 · plain	🥇 264 _{(99 MiB / 17.1% CPU)}	264 _{(99 MiB / 17.1% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	264 _{(160 MiB / 21.3% CPU)}	264 _{(160 MiB / 21.3% CPU)}
Early response (origin writes after first request chunk)	HTTP/1 · TLS	HTTP/1 · plain	🥇 6,507 _{(84 MiB / 43.0% CPU)}	6,881 _{(84 MiB / 43.0% CPU)}	347 _{(137 MiB / 24.9% CPU)}	419 _{(137 MiB / 24.9% CPU)}	3,256 _{(117 MiB / 39.5% CPU)}	3,606 _{(117 MiB / 39.5% CPU)}
Early response (origin writes after first request chunk)	HTTP/2 · TLS	HTTP/1 · plain	🥇 5,011 _{(153 MiB / 48.6% CPU)}	5,011 _{(153 MiB / 48.6% CPU)}	0 _{(139 MiB / 24.8% CPU)}	383 _{(139 MiB / 24.8% CPU)}	2,967 _{(97 MiB / 39.6% CPU)}	3,184 _{(97 MiB / 39.6% CPU)}
Early response (origin writes after first request chunk)	HTTP/3 · QUIC	HTTP/1 · plain	🥇 2,153 _{(125 MiB / 42.8% CPU)}	2,256 _{(125 MiB / 42.8% CPU)}	Not possible (no QUIC)	Not possible (no QUIC)	1,874 _{(154 MiB / 53.3% CPU)}	2,034 _{(154 MiB / 53.3% CPU)}
Duplex (both directions live)	HTTP/2 · TLS	HTTP/2 · TLS	🥇 784 _{(124 MiB / 13.2% CPU)}	1,270 _{(124 MiB / 13.2% CPU)}	Not possible	Not possible	18 _{(120 MiB / 30.7% CPU)}	2,135 _{(120 MiB / 30.7% CPU)}
Duplex (WebSocket / extended CONNECT)	HTTP/1 · TLS	HTTP/1 · plain	🥇 32,785 _{(97 MiB / 40.8% CPU)}	32,785 _{(97 MiB / 40.8% CPU)}	19,252 _{(138 MiB / 24.9% CPU)}	19,803 _{(138 MiB / 24.9% CPU)}	30,820 _{(85 MiB / 43.6% CPU)}	30,820 _{(85 MiB / 43.6% CPU)}

Linux

Scenario	Client	Origin	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
Slow consumer (256 KiB GET, throttled client read)	HTTP/1 · TLS	HTTP/1 · plain	🥇 468 _{(115 MiB / 9.5% CPU)}	468 _{(115 MiB / 9.5% CPU)}	416 _{(96 MiB / 9.6% CPU)}	416 _{(96 MiB / 9.6% CPU)}	418 _{(138 MiB / 13.6% CPU)}	418 _{(138 MiB / 13.6% CPU)}
Slow consumer (256 KiB GET, throttled client read)	HTTP/2 · TLS	HTTP/1 · plain	473 _{(131 MiB / 17.8% CPU)}	473 _{(131 MiB / 17.8% CPU)}	462 _{(96 MiB / 17.3% CPU)}	462 _{(96 MiB / 17.3% CPU)}	🥇 474 _{(146 MiB / 23.5% CPU)}	474 _{(146 MiB / 23.5% CPU)}
Slow consumer (256 KiB GET, throttled client read)	HTTP/3 · QUIC	HTTP/1 · plain	🥇 474 _{(125 MiB / 34.3% CPU)}	474 _{(125 MiB / 34.3% CPU)}	119 _{(100 MiB / 11.4% CPU)}	238 _{(100 MiB / 11.4% CPU)}	472 _{(193 MiB / 40.0% CPU)}	472 _{(193 MiB / 40.0% CPU)}
Early response (origin writes after first request chunk)	HTTP/1 · TLS	HTTP/1 · plain	🥇 5,039 _{(149 MiB / 45.3% CPU)}	5,039 _{(149 MiB / 45.3% CPU)}	3,904 _{(98 MiB / 49.4% CPU)}	3,904 _{(98 MiB / 49.4% CPU)}	3,425 _{(175 MiB / 55.3% CPU)}	3,425 _{(175 MiB / 55.3% CPU)}
Early response (origin writes after first request chunk)	HTTP/2 · TLS	HTTP/1 · plain	🥇 3,661 _{(233 MiB / 44.1% CPU)}	3,661 _{(233 MiB / 44.1% CPU)}	0 _{(103 MiB / 24.6% CPU)}	1,803 _{(103 MiB / 24.6% CPU)}	2,370 _{(148 MiB / 47.6% CPU)}	2,570 _{(148 MiB / 47.6% CPU)}
Early response (origin writes after first request chunk)	HTTP/3 · QUIC	HTTP/1 · plain	🥇 3,018 _{(193 MiB / 43.5% CPU)}	3,018 _{(193 MiB / 43.5% CPU)}	0 _{(114 MiB / 24.7% CPU)}	545 _{(114 MiB / 24.7% CPU)}	2,232 _{(262 MiB / 46.7% CPU)}	2,232 _{(262 MiB / 46.7% CPU)}
Duplex (both directions live)	HTTP/2 · TLS	HTTP/2 · TLS	🥇 185 _{(124 MiB / 9.0% CPU)}	282 _{(124 MiB / 9.0% CPU)}	Not possible	Not possible	138 _{(139 MiB / 44.6% CPU)}	1,882 _{(139 MiB / 44.6% CPU)}
Duplex (WebSocket / extended CONNECT)	HTTP/1 · TLS	HTTP/1 · plain	35,088 _{(121 MiB / 44.5% CPU)}	35,088 _{(121 MiB / 44.5% CPU)}	🥇 39,303 _{(97 MiB / 37.1% CPU)}	39,303 _{(97 MiB / 37.1% CPU)}	32,013 _{(122 MiB / 44.9% CPU)}	32,013 _{(122 MiB / 44.9% CPU)}

Slow consumer is sleep-bound; H1/H2/H3 sit in the same band. Early-response H1/H2/H3: TWP leads (H1 early ≈ 2.00× / 1.47× YARP Win/Linux). Duplex H2: YARP leads by design — Win ≈ 0.59× (1,270 / 2,135), Linux ≈ 0.15× (282 / 1,882); irreducible concurrent-copier cell (see IO model). WebSocket: TWP÷YARP Windows ≈ 1.06×; Linux nginx leads.

TLS termination cost (H1 TLS → cleartext origin)

Isolates keep-alive tiny GET vs new connection per request (handshake-dominated) vs keep-alive 256 KiB. Product comparison uses RPS and end-to-end latency; TWP can also capture ClientTlsTiming when TWP_RPS_CAPTURE_TLS=1 (child process) — nginx/YARP have no equivalent hook.

Windows

Median of 3 repeats on windows-latest @ 9d7c2966. Source: Actions 32866723562 (compare-tls-cost). Absolute RPS on GHA swings hard; prefer TWP÷YARP.

Workload	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
Keep-alive · tiny GET	🥇 20,709 _{(82 MiB / 48.3% CPU)}	20,709 _{(82 MiB / 48.3% CPU)}	9,096 _{(137 MiB / 24.8% CPU)}	9,158 _{(137 MiB / 24.8% CPU)}	17,934 _{(103 MiB / 48.1% CPU)}	17,934 _{(103 MiB / 48.1% CPU)}
New-connection · tiny GET	🥇 739 _{(65 MiB / 10.4% CPU)}	745 _{(65 MiB / 10.4% CPU)}	252 _{(136 MiB / 24.2% CPU)}	256 _{(136 MiB / 24.2% CPU)}	591 _{(93 MiB / 10.1% CPU)}	607 _{(93 MiB / 10.1% CPU)}
Keep-alive · 256 KiB GET	🥇 2,698 _{(87 MiB / 46.2% CPU)}	2,971 _{(87 MiB / 46.2% CPU)}	172 _{(137 MiB / 24.7% CPU)}	174 _{(137 MiB / 24.7% CPU)}	2,569 _{(134 MiB / 44.0% CPU)}	2,569 _{(134 MiB / 44.0% CPU)}

Linux

Median of 3 repeats @ 9d7c2966. Source: Actions 32866723562 (compare-tls-cost).

Workload	TWP sustain	TWP peak	nginx sustain	nginx peak	YARP sustain	YARP peak
Keep-alive · tiny GET	23,687 _{(104 MiB / 49.1% CPU)}	23,687 _{(104 MiB / 49.1% CPU)}	🥇 25,897 _{(95 MiB / 41.3% CPU)}	26,177 _{(95 MiB / 41.3% CPU)}	20,716 _{(133 MiB / 50.5% CPU)}	20,716 _{(133 MiB / 50.5% CPU)}
New-connection · tiny GET	962 _{(124 MiB / 47.5% CPU)}	973 _{(124 MiB / 47.5% CPU)}	🥇 1,005 _{(96 MiB / 44.2% CPU)}	1,008 _{(96 MiB / 44.2% CPU)}	941 _{(148 MiB / 45.8% CPU)}	941 _{(148 MiB / 45.8% CPU)}
Keep-alive · 256 KiB GET	🥇 2,690 _{(126 MiB / 36.5% CPU)}	2,690 _{(126 MiB / 36.5% CPU)}	1,749 _{(96 MiB / 53.6% CPU)}	1,749 _{(96 MiB / 53.6% CPU)}	2,146 _{(172 MiB / 45.9% CPU)}	2,146 _{(172 MiB / 45.9% CPU)}

All three workloads are >1.00× YARP on both OS. nginx leads Linux keep-alive tiny and Linux new-connection; TWP is second, YARP third.

Other measurements

What	Result
HTTPS TTFB vs direct (median, 14 hosts)	Cold ≈ parity (−1 ms); warm −25 ms (proxy faster)
HTTP/1 loopback GET (no body intercept)	~128 µs, ~9.9 KB allocated / request
Basic example footprint (Release, after load)	~74 MB working set · ~24–29 MB private bytes

dotnet run -c Release --project benchmarks/Titanium.Web.Proxy.Benchmarks -- --filter '*Throughput*'

Local laptop BDN @ 9d7c2966 (Release):

Benchmark	Setup	Mean	Allocated / op
HTTP/1 GET through proxy	Passthrough	128 µs	9.9 KB
HTTP/2 multiplexed GETs	10 concurrent streams	253 µs / batch	~4.4 KB / request

Raising limits on large hosts

There is no artificial upper clamp on server defaults. Per-endpoint overrides:

Knob	Scope	Default	Override
`ProxyServer.MaxCachedConnections`	process, per upstream host	128	any ≥ 1
`ProxyEndPoint.MaxCachedConnections`	endpoint → pool depth for that EP’s sessions	null (use server)	e.g. `256` on reverse EP
`ProxyEndPoint.MaxConcurrentClients`	endpoint admission	null (off)	any ≥ 1
`ResourceLimits.MaxConcurrentStreamsPerConnection`	H2 streams	256	`ProxyResourceLimits.Create(...)`
`TransparentQuicProxyEndPoint.MaxInboundBidirectionalStreams`	H3	100 (probe uses 256)	property on EP
`ForwardCleartext`	transparent TLS terminate	false	`true` + decrypt

proxy.MaxCachedConnections = 512;
proxy.ResourceLimits = ProxyResourceLimits.Create(
    /* … */,
    maxConcurrentStreamsPerConnection: 1000,
    maxCachedConnectionsPerHost: 512,
    /* … */);

var ep = new TransparentProxyEndPoint(IPAddress.Any, 443, decryptSsl: true)
{
    ForwardHost = "127.0.0.1",
    ForwardPort = 8080,
    ForwardCleartext = true,
    MaxCachedConnections = 256,
    GenericCertificateName = "example.com"
};
ep.BeforeSslAuthenticate += (_, a) =>
{
    a.UpstreamHttpProtocol = UpstreamHttpProtocol.Http11;
    a.AllowHttpProtocolTranslation = true; // HTTP/2 client → HTTP/1 origin
    return Task.CompletedTask;
};

Performance

Performance

Contents

Measurement environment

Windows (GitHub-hosted windows-latest)

Linux (GitHub-hosted ubuntu-latest)

Saturation control

Block A — H1 plain

Block B — H2 TLS→H1

Block C — H3→H1

Windows — Titanium vs nginx vs YARP

Reverse

MITM (TWP only)

Linux — Titanium vs nginx vs YARP

Reverse

MITM (TWP only)

Tiny JSON reverse is nginx’s best case on Linux

Why isn’t HTTP/3 > HTTP/2 > HTTP/1 in raw RPS?

Heavier reverse workloads

Windows — heavier reverse GET (64 KiB / 256 KiB)

Linux — heavier reverse GET (64 KiB / 256 KiB)

Windows — POST 64 KiB request + 64 KiB response

Linux — POST 64 KiB request + 64 KiB response

Windows — lossy / high-RTT (H2 HOL / H3 loss)

Linux — lossy / high-RTT (H2 HOL / H3 loss)

Architecture-sensitive

Windows

Linux

TLS termination cost (H1 TLS → cleartext origin)

Windows

Linux

Other measurements

Raising limits on large hosts

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Windows (GitHub-hosted `windows-latest`)

Linux (GitHub-hosted `ubuntu-latest`)