it's more fun to emulate

[smbhax]

Flycast

Notes to myself I cobbled together yesterday on optimizations or supposed optimizations (I haven’t done comparison testing for all of these) particularly for input lag in the Dreamcast emulator Flycast–I’m using the Windows version:

(Have to remember to hit the “Done” button at the top left of the Settings window to save settings changes!)

• Video - Delay Frame Swapping
  I unchecked it; apparently Flycast Delay Frame Swapping - Cores - Libretro Forums having it on may cause stuttering and “you only need it enabled when threaded rendering is on”

• Advanced - Other - Multi-threaded emulation
  I unchecked it; apparently “threaded rendering” Threaded rendering adds a frame of input lag · Issue #738 · libretro/flycast · GitHub adds a frame of input delay when enabled, and this was the only setting that seemed like it might be that

• Video - Texture Upscaling - Max Threads
  I’m not using texture upscaling anyway (Texture Upscaling set to “1”), but this was the only other option seeming to refer to threads, so I changed it from 3 to 1 just in case

• Video - Graphics API - Vulkan
  Several sources ( Input lag with Flycast? - Development - Libretro Forums , Help:Flycast GGPO - Mizuumi Wiki for instance ) mention Vulkan as the low-latency option here (the other options are OpenGL, DX9, and DX11, which I think was the default)

• Video - VSync
  I unchecked it; was mentioned in documentation http://flycast.dojo.ooo/faq.html#input-latency as the thing to do for minimizing input delay

• limit fps to 59.94
  Limiting the emulator’s framerate without using VSync is not a function Flycast has, although the doc was hopeful on adding it some day; recommended doing it via video card settings–my Nvidia Control Panel only allows forcing integer frame rates though–or Riva Tuner Statistics Server Guru3D RTSS Rivatuner Statistics Server Download 7.3.5 Beta 5 – I installed it, seems okay

After doing that stuff (didn’t try before), rough comparison testing gave me 5 frames of input delay in Soul Calibur on an actual Dreamcast, vs 3 frames in Flycast.

videogame things you think about a lot lot lot

That “+2 frames delay via emulation” was what I picked up from reading a few scattered Google results. But in my own just-now preliminary rough test, in JP SoulCalibur I got 5 frames of input delay on DC, and 3 frames of input delay in Flycast on my laptop.* Used HRAPV 2017 stick for both. Well heck! That was with vsync off of course, so there’s some tearing, but jeez I’ll take that, that’s nuts. Stays the same in Flycast even if I turn on widescreen and crank up the internal resolution to the…

Two other supposed optimizations I made:

• In Nvidia Control, 3D Settings - Program Settings, I set flycast.com to
  Low Latency Mode = Ultra
  Power Management Mode = Prefer Maximum Performance

• In Windows Explorer, I right-clicked flycast.exe, selected Properties, and in the Compatibility tab of the Properties window, checked “Disable fullscreen optimizations”