I'm old enough to remember that when Diablo came out, it seemed to be running too fast. This was before 3D video cards were mainstream (which happened with the Voodoo and Quake in 1997 maybe?).

I was working a lot with blitters at that point and running into speed issues on the Mac because Apple liked to release machines with half-width busses, which cut memory throughput by almost half. I'd be lucky to get 60 fps on a fullscreen 640x480 blit in 256 colors on a 68k Mac, but PCs seemed to do it trivially, and also do more with masking and color mapping at nearly the same speed.

Even PowerPC Macs ran between 2-10 times slower than their Pentium counterparts on tons of games. For example, Descent ran at 10 fps or whatever and was barely playable on a PPC 601, but ran great on a 100 MHz Pentium. Even Duke Nukem 3D ran full speed on a 100 MHz 486dx4. That could not have all simply been due to a lack of optimization on the Mac side.

This is all from memory so take it with a grain of salt. But I'm mildly curious what kind of approaches went into their blitting, and if they used things like palette animation (which wasn't available on the Mac because Apple put a blocking call on the palette change, which synced it to the refresh rate, although I never tried it from another thread because I don't think it was thread-safe).