For all Virge cards is frequency what counts. With Virge/GX you have higher chance for higher frequency (better memories). Here's some results from mine old tests....
Virge DX (86C375) - 4MB EDO 1cycle 3,5ns memory and clock 50,11Mhz - Eagles
DIAG Text - 29,19 MB/s
DIAG Graphic - 21,38 MB/s
Quake 320x240 - 129,6 FPS
Quake 360x480 - 62,8 FPS
Quake 640x480 - 20 FPS
GLQuake 320x240x16 - 15,6 FPS
GLQuake 640x480x16 - 4,9 FPS
Unreal Software 640x480x16 - 41,65 FPS
Virge GX (86C385) - 4MB SGRAM 0ns memory and clock 73,38MHz - Gainward
DIAG Text - 47,66 MB/s
DIAG Graphic - 29,88 MB/s
Quake 320x240 - 151,4 FPS
Quake 360x480 - 75,8 FPS
Quake 640x480 - 19,9 FPS
GLQuake 320x240x16 - 17,8 FPS
GLQuake 640x480x16 - 5,7 FPS
Unreal Software 640x480x16 - 43,65 FPS
Fastest Virge/DX i seen was Diamond Stealth 3D 2000 Pro with 4MB 72,19MHz EDO 1cycle 0ns. But most cheap cards are somewhere between 50-55MHz.
Not only mine graphics cards collection at http://www.vgamuseum.info