leileilol wrote:

Is Voodoo5's hyped up T-Buffer literally the accumulation buffer through marketing?

Doubtful. T-Buffer requires multiple chips with their own frame-buffers and each one can do/does independent processing for AA or motion-blur (where supported); it works in real-time and afaik is not supported on the single-chip hardware (like the 4500). The Sony GS may use this feature, or something very similar to it, for the DOF/motion blur effects it can do with some games (like GTA Vice City and Gran Turismo 3).

Here's a tutorial that looks at it more in-depth:
http://www.cse.msu.edu/~cse872/tutorial5.html
And this appears to cover it fairly well too:
http://www.forejune.com/stereo/samples10.pdf (section 10.1 specifically)

This site (http://www.saschawillems.de/?page_id=100) has a demo and the description mentions that many cards emulate the Accum buffer in software, which means a big performance hit. My Quadro FX 1700 is running it at 60-65 FPS (and if GPU-Z is to be believed, it appears to be doing it in hardware, as the GPU loading goes up substantially with it running); can try it on a GeForce if I remember.

I could not, however, find a definitive list of games that may use this buffer.

EDIT

Found an older article about T-Buffer with illustrations and the "why they aren't the same" hit me:

OpenGL Accumulation Buffer requires a frame to be rendered and then moved to it (images aren't rendered directly into it), and this can be done serially, so your GPU renders 1 then 2 then 3 then 4, etc in order and puts them into accum for whatever processing is done. T-Buffer has each GPU capable of rendering complete frames into frame buffer, so it would render 1 and 2 and 3 and 4 all at once, and then do whatever it wanted to do.

Here's the article I dug up from Anand (nice illustrations):
http://www.anandtech.com/show/350

There's a two-part Beyond3D article on T-Buffer that probably has more depth, but less graphics.