Sure, you can just send it garbage but it still takes up bandwidth. On the PS2 I can just send a single byte GENERATE_10000_FLAKES and it'll do it.
I just wanted to point out that although vertex shaders can't create vertices, as long as you know the final number of verts you can usually do the same thing.
You can also set the DMA length to 0 on xbox so it repeatedly sends the same word over and over, and I'm unsure if that would be cached, saving you the bandwidth. Sending single words over is not really significant anyway.
Hey, it's the only thing the PS2 has going for it so I'm gonna defend it till the day I die .
I agree, in general the flexibility of the VU's is nice. Although I have to say latencies on the instructions are such that scheduling by hand can be pretty painful. Of course compared to writing efficient uCode for an N64 it's relatively trivial.
Life is easy for an Xbox programmer.
Hmm not sure I agree with that, the challenges are somewhat different and don't revolve around managing DMA lists, but getting that last 10% out of any piece of hardware is far from easy.