> 32-bit binaries will require SSE2. Minimum CPU required will be Intel Pentium 4, AMD
> Opteron, AMD Athlon 64, or equivalent.
> Requiring SSE 2 improves performance and makes behaviour of 32-bit and 64-bit builds
> more consistent. Note that this only affects our packaged binary releases – by
> default, 32-bit x86 builds won’t require SSE. You’ll just have to compile MAME
> yourself if the SSE 2 requirement is a problem for your use case. However, recent
> MAME versions are unlikely to perform well on x86 CPUs that predate SSE 2 support.
I checked through my collection of old computers to see what could be affected, and only found a bunch of Compaq C600 celerons running Windows 2000 Pro. While it might be possible to install XP, the fact that XP requires registration discourages experimentation. Even if XP was on the machine MAME would crawl, rendering the exercise futile.
All in all, this is a sensible and logical change.