[Beetle PSX HW] Why is software rendering faster than OpenGL/Vulkan?

Libretro Cores
#1

So I played Castlevania : Symphony of the Night and Megaman X4 on Beetle PSX HW yesterday, on a laptop with Linux in DRM / KMS mode. I noticed a lot of slowdowns and hiccups both with OpenGL and Vulkan renderers (for Vulkan it was not in KMS mode, since it’s not possible yet), but when I switched to the software renderer, all the problems were gone, the games ran perfectly smoothly. Why ? I thought 3D accelerated renderers were supposed to be faster. Plus, I had graphical glitches on Megaman X4 sprites (both games are 2D games) on OpenGL, that also disappeared in software mode.

My laptop uses an integrated graphics chip (Haswell Core i7).

#2

They’re lighter on the CPU but harder on the GPU. The integrated graphics might not be strong enough.

2 Likes
#3

Oh, that makes sense, especially since I also use a CRT shader ! Thanks for the explanation Hunterk !