Thank you Marius,
Do I need to use GEM? I'm not doing anything with video, or graphics, I'm working only with audio. What I'd like to do in a first stage is to send to the GPU a set of data (harmonic peaks from live signals) and do some calculations there, then read back that into the program and proceed according to the results. In a second stage, the FFT and the spectral analyis could be performed there too. Chris mentioned that latency might be an issue since reading data from the GPU is slow, I don't know much about it but I think it shouldn't be since many cards can (and in fact must) use the main memory, so reading from memory should be as fast as it is when I read it with the CPU.
Also, I'm working in Mac OS 10.5, using Miller's version of Pd. Have you have any problems with Leopard and your patches?
Thank you again, and I'll read the patches you post to see if I can get more ideas from them...
Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com