PC optimization

To reduce desyncs, frame drops, and stuttering:

General advice

• Follow https://iidx.org/infinitas_pc - do it for spice(64).exe instead of bm2dx.exe, of course.
• Having a powerful PC with expensive CPU and GPU will not automatically let you run these games better. In fact, it can actually run worse - read below.

CPU

• Set Windows power profile to High Performance to keep the processor frequencies high. Arcade cabinets run with similar configurations where CPUs are held at maximum frequency; some of these games depend on this aspect to keep a steady framerate. IIDX, SDVX, and Nostalgia are known to be heavily affected by this. Make sure you turn it back to normal profile when done playing.
  • Instead of setting an entire profile, you could also edit an existing profile and change Minimum processor state to 100%.
• Use Process Affinity (-sp2x-processaffinity) to avoid using the lower-numbered processors.
  • Avoiding the first physical core is especially helpful since it tends to be busy with various affinitized work and drivers.
• Process Priority (-sp2x-processpriority) can help but it's recommended that you just leave it to the default.
• If log.txt tends to be spammed with messages, it can affect performance; set Log Level (-loglevel) to Fatal if this becomes an issue.
  • Remember to set it back to the default if you want to share log.txt with others for troubleshooting.
• If you're on a laptop, make sure it's plugged into a power source.

GPU

• For NVIDIA GPU, use Add NVIDIA application profile (-sp2x-nvprofile) option.
  • This will attempt to automatically disable G-SYNC and set power mode to maximum performance.
• Manually turn off VRR features - G-SYNC, FreeSync, Adaptive Sync should be always OFF.
• Manually set GPU to maximum performance - most games will greatly benefit from this for keeping a steady frame rate.
  • This is especially helpful for high-end GPUs, because they will downclock aggressively for not-so-demanding games (like the games supported by spice) to reduce heat / power.
• If your laptop has switchable graphics (iGPU + dGPU), make sure it's set to use the dGPU for spice.
• Play at the right refresh rate; 60Hz for most games, and 120Hz for IIDX/SDVX when enabled.
  • Sure, you can boot the game with various hacks at different refresh rate (like 165Hz) but there is no guarantee that the game will behave correctly.

Audio

• Prefer to use exclusive WASAPI or ASIO, and avoid shared mode WASAPI whenever possible. See this page for more details.