Just tried this today. Nothing fancy, just informal testing of the Phil's Dos benchmark programs on two different machines. One was a Pentium 66, Batman's Revenge with 256K cache and 32MB 60 ram and Phoenix Bios, the other a Micronics branded Intel HX with an Intel 233Mhz cpu, 64MB 60ns ram, 512K cache, also with a Phoenix BIOS. Both have their latest known BIOS. Both were booted from the same CF card with DOS 6.22, no drivers or memory managers, or anything. Just F5 to skip Confi.sys and Autoexec.bat. The card is an ET4000/W32p from an unknown brand that I largely bought on a whim.

The results were, for me, surprising.
Intel 233
1MB Dram
Quake 320x240 51.8
Quake 360x480 20.8
Doom max details 896 / 83.359
3dbench 1.0c 146.6
Chris' 3D benchmark 640x480 38
PC Player 640x480 21.2
2MB DRAM
Quake 320x240 51.9
Quake 360x480 21
Doom max details 880 / 84.875
3D bench 1.0c 164.4
Chris' 3D benchmark 38
PC Player 640x480 21.5

Pentium 66
1MB Dram
Quake 320x240 18.9
Quake 360x480 8.5
Doom max details 1849 / 40.394
3dbench 1.0c 68.4
Chris' 3D benchmark 640x480 16.7
PC Player 640x480 8.2
2MB DRAM
Quake 320x240 18.9
Quake 360x480 8.5
Doom max details 1837 /40.658
3D bench 1.0c 68.4
Chris' 3D benchmark 16.7
PC Player 640x480 8.2

The difference on the Pentium 66 system is basically nil. The effect of memory interleaving is a little more pronounced on the Pentium 233, but even there it isn't earth shattering. I wonder how many would have been using an Et4000 on a system like that. Possibly people who upgraded a bit at a time. It was nice to see something finally edge out the Number Nine Vision 864.

I have an ET4000 VLB coming in a couple weeks, I may try this again with my 486 system.