[StillBored]

Which brings up another fact, which was that microsoft disabled the cache on cyrix processor in one of the versions of windows NT (3.51 or 4?). And so you had to download a driver from Cyrix to turn it back on. But that didn't keep various people from claiming it's perf sucked in windows NT too.

IIRC the official excuse when this became public was that a MS engineer turned it off because one of their test machines couldn't complete a stress test with it enabled, but later it turned out the root cause was a bad motherboard. The curious part being that it didn't result in MS immediately issuing a hotfix to turn the cache back on.

edit: found one of the articles mentioning this. https://www.tomshardware.com/reviews/bananas,9.html

Apparently it was just writeback mode that got disabled, either way that link mentions a 30% perf hit.