I've just been using topbench, as this isn't hugely important to me, but I thought some dos and early windows games would need some form of cache in order to run at the speeds quoted in topbench? E.g some games might run at 486-66 speed with cache disabled but some may depend on it and run much slower.

Also, just an observation I've made, disabling both sets of cache in the bios of a 486-100, p90 and 9166 all seem to limit the cpu to the same 386sx speed (16 or 33 iirc) - does this sound accurate?