Imgur is blocked in my country....

Use the attachment feature built in to the forum and link the images inline. External image hosts are :puke:

Lostdotfish wrote on 2026-05-07, 15:02:

Imgur is blocked in my country....

Use the attachment feature built in to the forum and link the images inline. External image hosts are :puke:

Thanks. I've attached the photos directly.

Sorry for the inconvenience. When I first got online in my formative years I had it drilled into my head to be conscientious about how I linked images. But that was circa 2002 so things have changed a lot since then.

Can you post a clear image of each card so I can see the memory ICs?

Are they they same brand on both cards?

Lostdotfish wrote on 2026-05-07, 16:39:

Can you post a clear image of each card so I can see the memory ICs?

Are they they same brand on both cards?

The cards appear identical to me, but it's possible I've overlooked a small detail.

To debug this I'd suggest simplifying the setup as the two cards might have different default settings.

What happens when everything is set to 60Hz refresh and vsync on, and is does the glitch change when running at other refresh rates?

Have you tried swapping the cards over and letting the other one be the master card?

What else do you have on the PCI bus? Could another device be causing slow downs?

I would remove any other PCI cards and test again.

The memory ICs are identical. Are these the cards with high density RAM on one side? They are laid out like 8MB cards (no RAM on the reverse of the card)

My first inclination is that this is an SLI cable problem... like something is physically inverted or out of place.

If the SLI cable you are using isn't keyed (with the little nub in the center) the cable might be installed backward? These types of connectors are intended to go one direction and are not straight through (top row on one side is the bottom row on the other). I have no idea if this would make any difference for SLI, it's just something to take a look at.

My apologies if this doesn't make sense in this context... I ran into this recently when trying to extend an IDE connection on an old backplane and came to the realization that IDE\Floppy style IDC connectors flip top to bottom like this when both are male. They cannot, for example, be chained together with gender changers without the pinout ending up totally wrong.

(Also, I have a bit of a problem when it comes to inverting things... it just makes my brain break. Probably related to some undiagnosed dyslexia.)

MattRocks

What happens when everything is set to 60Hz refresh and vsync on, and is does the glitch change when running at other refresh rates?

May you help me find where v-sync is in this 3dfx V2-1000 menu? My refresh rate appears to be locked at 60hz, but I could find no v-sync toggle anywhere. (See attached image #1, VsyncWhere.jpg)

Have you tried swapping the cards over and letting the other one be the master card?

Yeah, I tried flip flopping card A and B several times; scooting them up a PCI lane, scooting them down; putting the 2D card on top of the Voodoo 2s, putting it beneath; connecting the pass-through cable and VGA to the Voodoo 2 closest to the 2D card, and then switching pass-through and VGA out to the Voodoo 2 farthest away. The outcome never changed.

What else do you have on the PCI bus? Could another device be causing slow downs?
I would remove any other PCI cards and test again.

On this machine’s PCI lanes I have:

Voodoo 2 #1
Voodoo 2 #2
2D card
sound card

A moment ago I just uninstalled drivers for and removed the sound card and nothing changed. The issue persists.

The memory ICs are identical. Are these the cards with high density RAM on one side? They are laid out like 8MB cards (no RAM on the reverse of the card)

This question leads us to an interesting place. I’d like to dwell on this for a bit.

The eBay seller I purchased these from advertised them as 12 MB cards.

When I view each individually in this DirectX Diagnostic Tool that comes with Star Wars Episode One Racer, it reports 12 MB for each card.

(See image #2, 12MB_for_card_A_according_to_directx_diagnostic_tool.jpg)

(See image #3, 12MB_for_card_B_according_to_directx_diagnostic_tool.jpg)

With both cards in SLI, the DirectX Diagnostic Tool reports 16 MB.

(See image #4, 16MB_for_both_cards_according_to_directx_diagnostic_tool.jpg)

However, with both cards in SLI, Windows system info reports 4 MB of frame buffer memory and 8 MB of total texture memory. Is this abnormal? It seems that way to me, but I’d like to run that past a Voodoo 2 veteran first.

(See image #5, 4MB_and_8MB_for_both_cards_according_to_system_info.jpg)

Ozzuneoj

My first inclination is that this is an SLI cable problem... like something is physically inverted or out of place.

Yes, this is exactly what I was thinking. But I’m not a Voodoo 2 SLI veteran, so I don’t have much experience diagnosing these. It could be that what my intuition tells me is not accurate.

If the SLI cable you are using isn't keyed (with the little nub in the center) the cable might be installed backward? These types of connectors are intended to go one direction and are not straight through (top row on one side is the bottom row on the other). I have no idea if this would make any difference for SLI, it's just something to take a look at.

My cable is keyed.

My apologies if this doesn't make sense in this context... I ran into this recently when trying to extend an IDE connection on an old backplane and came to the realization that IDE\Floppy style IDC connectors flip top to bottom like this when both are male. They cannot, for example, be chained together with gender changers without the pinout ending up totally wrong.

(Also, I have a bit of a problem when it comes to inverting things... it just makes my brain break. Probably related to some undiagnosed dyslexia.)

Me too. I’m not sure if it’s possible for my SLI cable to be homemade and for the guy who made it to have flipped the 3 wires in need of flipping with the wrong orientation. If that’s what he did, though, then when I made cards A and B trade places, wouldn’t that have fixed it? Wouldn’t that be the same as making the SLI cable “flip polarity”? But then I get confused when I think about it too much.

I did contact the seller, not to point fingers, but to gently ask him if he recognized what was wrong with my setup. Our back and forth went like this:

Me: You're not obligated to troubleshoot this for me, but if the issue is interesting to you, I made a vogons thread about it:Voodoo 2 SLI Setup Has Weird Interlacing Problem

Seller: The only insight I might have is that I used this jumper cable back in the day with 2 STB Blackmagic Voodoo2 cards.

Me: That’s helpful. Thanks.

I think his response is code for “I don’t want to troubleshoot this with you, just leave me alone and please don’t ask for a refund.”

Total memory on a Voodoo 2 = FB mem (4MB) + TM mem (4 or 8MB), so 4+8 is correct for a 12MB card.

Anayo wrote on 2026-05-09, 23:59:

MattRocks

What happens when everything is set to 60Hz refresh and vsync on, and is does the glitch change when running at other refresh rates?

May you help me find where v-sync is in this 3dfx V2-1000 menu? My refresh rate appears to be locked at 60hz, but I could find no v-sync toggle anywhere. (See attached image #1, VsyncWhere.jpg)

Sorry, I'm working off decades old memories as my Voodoo2 have not been found - what is behind the 'Advanced' button?

Edit: My Computer > Properties > Advanced > Environment Variables

VSynch on:

1SET SSTV2_VSYNC=1

VSynch off:

1SET SSTV2_VSYNC=0

Library of Voodoo1 SST options documented here (just replace 4Mb Voodoo "SST" with Voodoo2 "SSTV2"):
https://www.oocities.org/mechwarrior2_3d/Voodoo_SST_FX.htm

Some extra Voodoo2 SSTV2 options:
FX_GLIDE_LOD_DITHER
FX_GLIDE_ALLOC_COLOR
FX_GLIDE_ALLOC_AUX

I'm guessing, but maybe logout and login again to ensure changes are applied to your test. Having said all that, I recall a similar experience and swapping the master/slave arrangement resolved my complaint. My two 12Mb cards were from different vendors, acquired years apart, one new and one used. IIRC, my used one had a fuzzier output one was best used as a slave.