Compare Announced ATI Crossfire/Brook+ and CUDA

As several of you must have seen (e.g. at…m-computing.pdf
or ATI is coming to the stream computing party as well with the crossfire boards

Is anybody using these in trial versions? Is there a beta of Brook+ out?

I see a peak speed similar to G80 (500 vs. 330)

Also, there are 320 stream processors vs 128

Both architectures now only appear to have generic processors … no vertex and fragment

the local memory seems to be arranged a bit differently on ATI

Please post any info. you have or thoughts here …

I don’t know, but I’m certainly interested in this as well. Especially feature-wise. We all know that ATI and NVidia try to beat each other in speed every generation. Though it’s nice to know who is on top.

Can this CTM (with Brook+) do the same as CUDA? Why does ATI have more stream processors but comparable performance? Etc.

There must be someone that worked with both that can answer these, right :)

Processor frequency is much lower, something around 800 MHz. And, clearly, some other microarchitectural issues. Not much information about ATI cards/API.

It will be interesting how Brook+ is different than Brook (or at least the Stanford implementation of Brook for GPUs). I worked with Brook briefly before switching to CUDA, and that language also had a C-like syntax. It was far more constrained than CUDA, given that it was targeted at the previous generation of graphics cards.

What about writing directly to the framebuffer? Can the Crossfire boards do it? And what about the memory bandwidths?