Dear all the great 3dfx people out there,

There has been something on my mind which is kinda confusing.

It's about the size of Frame Buffers on VSA-100 cards.
At first these cards are bothering me:

1. 3dfx Voodoo5 5000 AGP/PCI 32MB 2x VSA-100
2. 3dfx Voodoo5 5500 AGP/PCI 64MB 2x VSA-100
3. 3dfx Voodoo5 6000 AGP 128MB 4x VSA-100
4. Quantum3D AAlchemy 4116 64MB PCI 4x Voodoo-500
5. Quantum3D AAlchemy 8164 512MB PCI 8x VSA-100

okay I do know is that the 4500's have 30MB for the @D as 3D and 2MB for the Frame buffer.

But what about the Voodoo's 5000, 5500 and 6000, is it so that the frame buffer is 2MB per VSA-100 or per card ???

My theorie is this:

3dfx Voodoo5 5000 AGP/PCI 32MB has 2x VSA-100 right , so it would then be 2x 16MB in total, which 2x 14MB for the 2D as 3D and 2x 2MB for the frame buffers per VSA-100 which equals a total of 28MB for the 2D/3D part and 4MB for the Frame buffer and it's logic that a Voodoo5 5000 has 32Megs of SGRAM.

3dfx Voodoo5 5500 AGP/PCI 64MB has 2x VSA-100, so it would thereticly be 2x 32MB per VSA-100 in total, asfor the 2D/3D part 30Megs of SDRAM per VSA-100 and 2MB per VSA-100 for the frame buffer, that's a total of 60MB for 2D/3D and 4MB for the frame buffer.

3dfx Voodoo5 6000 AGP 128MB has 4x VSA-100 as we all know hehe, so for the 2D/3D it has 4x 30Megs of SDRAM and 2MB per VSA-100 for the Framebuffer, which means a total of 4x 30MB SDRAM equals 120MB for the 2D/3D part and 4x 2MB per VSA-100 which equals 8MB for the Frame buffer.


Quantum3D AAlchemy 4116 64MB PCI has 4x Voodoo 500 with  4x 16MB, that would be 4x 14 MB for the 2D/3D part and 4x 2MB for it's frame buffer. which equals 52 MB for the 2D/3D part and 8 MB for it's Frame buffer a total of 64MB SGRAM.

Quantum3D AAlchemy 8164 512MB PCIhas 8x VSA-100 and 64Megs of SDRAM per VSA-100, so I was thinking it has 60MB's  per VSA-100 for it's 2D/3D part and 8x 2MB for it's massive frame buffer, which equals 480Megs of SDRAM for it's 2D/3D part and 16Megs of SDRAM for it's Frame buffer together that's a total of 512MB.


Yet I may be mistaken on my theorie, I really hope someone can give a clear answer how the memory really is devided on these cards.
This has been on my mind for years, but still I was confused if it was 2MB per VSA -100/101/200 & per Voodoo-500.

As far as I know the Banshee, V3 and VSA-100 all have a unified memory setup, the frame buffer isn't of fixed size.

so then it would be per card a different size? but a 5500 would not have the same size of frame buffer as a 5000 nor 6000?

a frame buffer depends on the bit depth and the resolution displayed. That's it (I think!) :P

Yep, that's correct.

The Voodoo1 and Voodoo2 were the only 3dfx Cards with pre-defined Framebuffers.

Voodoo1 : 2MB FB, 2 or 4MB TexMem
Voodoo2 : 4MB FB (8MB in SLI), 4 or 8MB TexMem

Banshee upto Voodoo5 : flexible Framebuffers (depending only on Resolution, Colourdepth and amount of Buffers; e.g. Double Buffer was normal, Triple Buffer or more was a hardly effective, and sometimes lag-inducing Tweak Option)

so it's possible that all of the memory of the Voodoo5 cards can be used as a frame buffer, like reso 2048 x 1536 x 32 in Quake 3 as an example? anyway that would be a very painfull state for the Voodoo5 5000 nor 5500...the 6000 would do that very well.

The Voodoo5 5000 would suffer the greatest, having only 16MB per VSA-100.

The Voodoo5 5500 and Voodoo5 6000 would show almost equal performance, with them having 32MB per VSA each.

A single 1600x1200 32bit Framebuffer requires already 7.68MB, with Double Buffering that's already 15.36MB.
(and no FSAA yet, 2x FSAA doubles the requirement, 4xFSAA quadruples it accordingly)

Only ~1.4MB remain for Textures on a Voodoo5 5000, lots of swapping at catastrophic speed.
The Voodoo5 5500/6000 would have ~17.4MB of TexMem remaining, which is about just sufficient swap-free for High Quality Textures of Quake3.

At 2048x1536x32, a Single FB already takes a whopping ~12.6MB, and 25.2MB with standard Double Buffering.
Possible with a Voodoo5 5500/6000, but only ~8.4MB remain as TexMem.
That means alot of swapping again, very low performance for both Cards.

That is in theory, the voodoo 5 will not go in this resulotion in 32 bit  ;) .16 bit however is not a problem runs at 52 FPS in Q3 if I remember correct.

Theoretically speaking, how would this be for a V5 with 128MB of RAM?

yeah or even a Voodoo4 4500 with 64MB like this little critter:

http://denisfak.homestead.com/files/v4564.jpg

this card seems to be the cleaver work of DenisF :)

Not sure, since only the later Voodoo4's were equiped with the higher capacity RAM's; IMHO early models shipped with those 8 chips mounted, still makes for only 32MB.

Since Q3 runs with only some 16-20MB Textures in average (High Quality Setting), the additional RAM wouldn't help on a 32MB card or higher.
UT2003 would be a whole different story, however.

I believe there's still a gain in framebuffer memory thanks to the SLI, as on voodoo 2?

Each VSA/100 will store the bands of scanlines it renders.
Let's say 20MB are eaten by the textures (which are replicated for every VSA/100).

on  a V4 4500 you would have 12MB of framebuffer memory ;
on  a V5 5500,  24MB of effective framebufffer memory ;
and 48MB on a V5 6000
(V5 5000 would be the worst, already texture swapping, only the V4 4200 could be a little worse)