More video card testing...
Tested a bunch of Virge cards today. Much like the Trio64V+, it seems that there are massive swings in performance from one Virge DX or GX card to another. I'm guessing it is as least partially due to the EDO being configured for 1-cycle or 2-cycle mode. I see that over on the VGA Museum there is mention of cards being in 1-cycle mode, but this is one of the few times I have seen anyone mention this.
I find it kind of funny that this isn't something that is ever talked about. People will plan entire builds around 10% performance differences between graphics chips on a benchmark chart, and then most will apparently just get any card with that chip and toss it in their retro PC, not realizing that there can be a 300% swing (that is not a typo) in benchmark performance from one nearly identical card to another. I bet a huge percentage of purpose-built retro systems running S3 (or other?) cards from this era have massively gimped performance because they happened to get a card that is set up for 2-cycle EDO.
Anyway... after dealing with those, I tested a couple of Virge VX and a Vision 968. All three are Diamond branded cards, and, surprisingly, all of them have problems. Two are cosmetically flawless... so unless there is some minuscule broken solder joint somewhere, all I can think is that they have defective memory? Has anyone else noticed S3 VRAM-based cards being unreliable overall? I know that 3D performance and compatibility is absolutely horrid on the Virge VX due to this card being based on the original Virge (as opposed to the DX and GX which are massively improved), but it seems odd that I'd be having artifacts on the desktop and various other problems with so many similar but fairly expensive (for the time) cards.
One Virge VX (2+2MB) has graphical corruption on the bottom 3rd of the screen at higher resolutions. The other VX (2MB) does not, but it has pixelated artifacts in other areas, including an arrant pixel that follows the mouse cursor around. Weirdly, the Vision 968 (2+2MB) has almost the same corruption as the first VX covering the bottom 3rd of the screen at higher resolutions.
I noticed a post here where kixs says he has had a lot of problems with Vision 968 cards as well. Just wondering if anyone else has had a similar experience. In comparison, I have recently tested a few dozen other S3 cards (Trio64V+, Virge, DX, GX, Trio3D, etc.) that do not use VRAM and I may have had one or two that were defective, but it was due to physical damage. Bad RAM or un-fixable stability\artifacting issues were very rare with other cards from this period.