AFIAK, you need two VSA 100s to run 4x AA

I know that, it's just I thought 4x AA absence was not a hadware limitation, but a driver limitation instead, to avoid very low framerates on high resolutions. VSA-100 implements FSAA via multisampling, so maybe Voodoo4 could make 4x AA forcing it to render the same scene several times  ???, obviously a driver hack would be a must.

In spanish eBay, it's impossible to find a Voodoo5 for less than 60 Euros;. Recently I saw a PCI one with an initial price of 80 Euros and Buy it now! price of 90 Euros; (not to mention that a Voodoo5 won't fit into my old AT case).

edit : symbol Euros

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VSA-100 implements FSAA by SUPERSAMPLING (subjective it looks even better than multisampling). but it also needs a higher fillrate. 4x FSAA needs a fillrate you could only get with 2 VSA-100 chips. That' it!  8)

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Take a look at this article:

http://www.nvworld.ru/docs/fsaa2-e.html

VSA-100's AA was officially named 'Rotated Grid Super Sampling', but technically it must be considered the first multisampling AA method.

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Let's examine this AA method closely. It is known by the name 'Rotated Grid Super Sampling' (RGSS). Based upon 3dfx T-Buffer technology which allows generating four frames at once and mixing them later to acquire wide variety of effects.

Voodoo5: is the first and only accelerator which supports T-Buffer technology, and therefore RGSS. The board has two VSA-100 chips, each of which can process and store one or two frames. Hence, we have two antialiasing modes: 4x and 2x.

4x Antialiasing mode: unlike standard supersampling, which is rendering one image in higher resolution, RGSS renders four identical images in a given resolution.

2x Antialiasing mode: another one antialiasing mode, which works faster but at the cost of quality. It processes only two frames to form final pixel using two samples.


This paper states that each VSA-100 can process and store up to a couple of frames, so a single chip would be unable to render the 4 simultaneous frames needed by 4x AA. But, is it actually a hardware limitation? With 32 Mb of RAM, a Voodoo4 has enough room to fit 640x480x16 quadruplicated front, back and z buffers, and still some free Mb for textures. That would be a very useful scenario for those graphic adventures or survival horrors which used static backgrounds and low resolutions. Performance will be downgraded to Voodoo1's, but those games were perfectly playable on Voodoo1.

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I'd rather think it's a limitation of T-buffer, which scales nicely with multiple chips


4x fsaa on voodoo4 would be great.. it would mean 8x fsaa on my v5 5500
but this won't be possible

and that would be as slow as 4X fsaa on a geforce2 MX, thus not very practicable, unless you want to play old glide game or get even better quality in quake 1&2

you might have noticed that you even can't use other t-buffer effects (soft shadows, motion blur etc..) on your voodoo4. that's because ONE VSA-100 isn't able to do that --> lower framerate, lower bandwith (thanks Lecram25  )
of course it would be cool to have 4x FSAA and the other effects on this card, but it wouldn't work well with most games..so -i state- it was just useless in the opinion of 3dfx.
my tip: buy a voodoo5  try the german ebay site if your's is too expensive.

I believe the geforce 2 and below use software AA... I remember when the voodoo 5 came out with the first true hardware FSAA...So nVidia had to compete; so they enabled AA via software...
Don't quote me on that...