No. The tearing is being caused by one card running out-of-sync of the other. Voodoo2 SLI works by having each card drawing alternating lines on your screen. This goes back to CRTs that used an electron beam to scan an image to the glass panel one line at a time from bottom to top. Each alternating line was drawn using information from a different Voodoo2 card. That's why it's called Scan-Line Interleave (a.k.a. SLI). The two cards need to run in sync with each other with frame buffers in order to draw the unified image properly. LCD panels would show this very badly - CRTs would have sort-of hidden this effect, but it would have still been there.

About the bend...I've seen cards to this too sometimes. As long as nothing actually breaks (cold solder joint) and all contacts and traces remain, then there's no reason to be concerned. Pics would, of course, help.

FFXIhealer wrote:

No. The tearing is being caused by one card running out-of-sync of the other. Voodoo2 SLI works by having each card drawing alternating lines on your screen. This goes back to CRTs that used an electron beam to scan an image to the glass panel one line at a time from bottom to top. Each alternating line was drawn using information from a different Voodoo2 card. That's why it's called Scan-Line Interleave (a.k.a. SLI). The two cards need to run in sync with each other with frame buffers in order to draw the unified image properly. LCD panels would show this very badly - CRTs would have sort-of hidden this effect, but it would have still been there.

About the bend...I've seen cards to this too sometimes. As long as nothing actually breaks (cold solder joint) and all contacts and traces remain, then there's no reason to be concerned. Pics would, of course, help.

Okay. I knew how SLI worked, I was just wondering if tearing was a common issue back in the day or if it indicated something wrong with either of my cards. I prefer to run with VSync off most of the time as VSync can induce latency/input lag.

I should mention that they are both STB Black Magic cards with 12MB. I'm not aware if it matters, but one has the standard 24 RAM chips, 12 on each side. The other is a later production model that consolidated the RAM to 12 chips on one side.

As for the bend, for now I've put together a ghetto fix using a plastic piece about 4.5cm tall to hold the second Voodoo2 up to a flat position. Would this fix the sagging over time or is it just going to do more harm than good?

No, the card was manufactured flat, so remaining flat is always preferable. It'll reduce strain on the individual components (capacitors, resistors, memory chips, etc).

And I have a pair of identical STB V2-1000 12MB cards. They are IDENTICAL, but I couldn't get SLI to work for shit until I replaced the STB drivers with the Fast Voodoo drivers I got from users here at Vogons. After I replaced the drivers, the whole SLI rig became 100% stable and working. It shouldn't matter whether your cards use 512KB chips or 1MB chips. Mine both have 1MB chips, by the way. What matters is the speed the memory chips operate at and that the cards operate at. 90MHz is the most stable, but some Voodoo2 cards were factory overclocked to 100MHz or could have that done via the driver settings page under Display Properties (such as the Diamond Monster 3D II). I leave mine at 90MHz and I get really good results anyway.

You mentioned that the tearing happens when you turn off Sync buffer swaps. Is there a reason you turned that off in the first place?

I describe it more as an interlacing effect rather than tearing. Most noticable at high FPS. Play games in settings that keep fps low and it should be less obvious. But don't game @ 200 fps for example.

The tearing effect is still very noticeable on a CRT. I prefer activate V-sync personally, I didn't experienced input lag (I don't even know if I ever experienced that on PC games. But that's just me, I'm not a pro gamer 🤣)

i have the same question about interlacing tearing. i have voodoo1 sli setup and encounter same issue when set fx_glide_swapinterval=0. if i run boards separately, moving objects edges are smooth, but in sli it's like rip-saw show. when fx_glide_swapinterval=1 image ok, but about 20% perfomance loss. perfomance is vulnerable point of v1, so i'd like to keep swap=0. may be there is exist some way to cope with this behaviour?

also got another issue with different brightnes on 640x480 and 800x600 resolutions. first one is light, may be too light, but second is too dark

tested in q2. tried latest diamod monster and IceMan Win9x Driver (V3.01.01). no difference

OT: Voodoo 1 SLI, as in one of those rare Quantum3D boards... or a modded regular V1s?

havli wrote:

OT: Voodoo 1 SLI, as in one of those rare Quantum3D boards... or a modded regular V1s?

Probably a mistype and v2 sli or indeed a quantum3d but i think it will be extremely hard to ''mod'' it on normal v1.

Extremely hard yes, but anthony is the master of 3dfx mods.... if such mod is possible, he is the one to perform it. 😈

I have two type of sli setups. Obsidian 100sb. And two modded 50sbs in sli. Both setups expose same behaviour

ElementalChaos wrote:

I should mention that they are both STB Black Magic cards with 12MB. I'm not aware if it matters, but one has the standard 24 RAM chips, 12 on each side. The other is a later production model that consolidated the RAM to 12 chips on one side.

It's possible like mentioned before the cards don't sync well or properly. It's always advised to use 2 identical cards to prevent this issue.
I also experienced the tearing and lines on 2 ocassions with my SLI, 1 time I had the SLI cable put in wrong and the other time my cards were overheating (or at least the primary, due a certain geforce 256 blowing it's heat on the Voodoo's). I fixed this last problem with a 3d printed fan mount in between 2 Voodoo's (and slightly above the primary). For a better description look at my pentium 2 build in my signature (includes pictures). This mount straightens and suports your Voodoo's .

There are a lot of clkdel variables. May be it will help to adjust synchronizing a bit

for expample, it's from q3d 200sbi:
SSTV2_FT_CLKDEL = 5;
SSTV2_TF0_CLKDEL = 7
SSTV2_TF1_CLKDEL = 7
SSTV2_TF2_CLKDEL = 7
SSTV2_SLIM_VIN_CLKDEL = 3
SSTV2_SLIM_VOUT_CLKDEL = 2
SSTV2_SLIS_VIN_CLKDEL = 3
SSTV2_SLIS_VOUT_CLKDEL = 2