Missing ROCm Support for RDNA2 Device Models (6950 XT, 6900 XT, 6900, 6750 XT, 6650 XT)

[gchriswill]

Platform

Windows

Lemonade Version

10.8.1

GPU / APU Model

PowerColor Red Devil AMD Radeon RX 6950 XT

Component

llama.cpp

Bug Description

std::string identify_rocm_arch_from_name(const std::string& device_name) in src/cpp/server/system_info.cpp is used to map an AMD GPU marketing name to its ROCm gfx architecture family. The RDNA2 detection branch (gfx103X) only includes four of the eight RX 6000 series model numbers:

device_lower.find("6800") || device_lower.find("6700") || device_lower.find("6600") || device_lower.find("6500") 

For the following RDNA2 dGPU models, std::string identify_rocm_arch_from_name(const std::string& device_name) returns an empty string instead of gfx103X:

Model
AMD Radeon RX 6950 XT
AMD Radeon RX 6900 XT
AMD Radeon RX 6900
AMD Radeon RX 6750 XT
AMD Radeon RX 6650 XT

Notes 📝:

I found this issue in version 10.8.0 due to the need for ROCm support for my dGPU model gfx1030.
Then the promising 10.8.1 with fix #2295 didn't worked for me.
After building the latest from main source, I still get the same "Unsupported GPU" when listing the backends.

Steps to Reproduce

1. Have a PC with any of these AMD RDNA2 dGPUs: 6950 XT, 6900 XT, 6900, 6750 XT, 6650 XT
2. Lemonade launches
3. Check available backend list via app or cli
4. Observe for ROCm "Unsupported GPU"
   • https://cdn.discordapp.com/attachments/1394403929973985413/1518730022184030421/Screenshot_2026-06-22_171846.png?ex=6a3cf54d&is=6a3ba3cd&hm=e88f2eeda7468984250aafda1a11855719a6f2ee7b843a99ca646f64f5f6a2ba

Expected vs Actual Behavior

std::string identify_rocm_arch_from_name(const std::string& device_name);

Device Models	Expected Result	Current Result
AMD Radeon RX 6950 XT	"gfx103X"	""
AMD Radeon RX 6900 XT	"gfx103X"	""
AMD Radeon RX 6900	"gfx103X"	""
AMD Radeon RX 6750 XT	'gfx103X"	""
AMD Radeon RX 6650 XT	'gfx103X"	""

Log Output

N/A

Additional Context

• ROCm support matrix for RDNA2 dGPUs (only supported on Windows)
  • Why have device model 6500 if no official support from ROCm?
• Initial findings:
  1. https://discord.com/channels/1392562559122407535/1394403929973985413/1518730021978640436
  2. Lemonade prevents use of ROCm backends because of built-in gfx1036 #2296
  3. gfx1201 unsupported with rocm (9070xt) #2302
  4. ROCm unavailable for gfx103X, gfx110X and gfx120X #2319
• Attempted Fixes:
  • fix(gpu): support wildcards in GPU detection logic #2295