Did you use ICD.EXE to disable the internal cache? (You mention ICD.exe in your related post here: Wing Commander I in 486 DX2-66 - Perfect Speed Attained!!)

I've tried disabling the internal and external caches on a 486, and discovered that the 486 can subsequently behave as if it were the speed of a 386. However, I didn't know about ICD.exe. Instead, I found both the disable internal and disable external cache options inside the BIOS set up area. Unfortunately, I can't remember the models of the motherboards used at the time of testing.

Yes, that's the one I used. It's easier to use these utilities (rather than doing it in bios) since you can enter the icd.exe and ice.exe commands at any time at the dos prompt. You can disable the internal cache - icd.exe, say before playing Wing Commander, and then re-enable it using ice.exe, for playing more resource intensive games, say Falcon 3.0.

Another point : Disabling the External cache doesn't change much. The most I've seen is the SI score falls by 1 - 3 points from the full speed, turbo-on setup.

Ah thanks! I didn't realise ICD.exe performed the same operation as entering the BIOS and manually adjusting the enabled/disabled value. ICD.exe sounds like a utility I need to download and try out. 😀