For Supreme Commander, there currently exists no “adequate” CPU. As with its predecessor Total Annihilation back in 1997, faster processors just delay the onset of low frame rates and slow game speeds.
— Dan’s Data. I first played TA when it came out in 1997 on Mark’s LAN between a Pentium 100 and a Pentium 200 MMX. It was downright painful, and you couldn’t run large games quickly until the era of the 450+ MHz Pentium III. SimCity 4 had the same problem, and might still.