Snow Leopard, OpenCL and Audio Applications

[DMJ]

I was reading about Snow Leopard and the various OS improvements Apple plans to introduce. While reading about Open CL:

From the apple SL site:
Another powerful Snow Leopard technology, OpenCL (Open Computing Language), makes it possible for developers to efficiently tap the vast gigaflops of computing power currently locked up in the graphics processing unit (GPU). With GPUs approaching processing speeds of a trillion operations per second, they’re capable of considerably more than just drawing pictures. OpenCL takes that power and redirects it for general-purpose computing."

I couldn't help but think about all the possibilities that extra CPU power could bring to an application like MIR. I know that there can be no official comment on the ramifications of this by any Apple developer. But surely this type of technology would help to reduce the need to have a dedicated machine running MIR.. Considering a top of the line graphics card like this runs for about $650 CAD (less then a i7 quad core processor)

Not having extensive knowledge of GPU's vs CPU's I'm unsure of how huge that impact would be, sure can't hurt though! 😊

So what do you guys thing about OpenCL?

[steff3]

OpenGL is interesting - though, in my opinion less for audio applications ... some points: - high end graphic cards are loud (cooler) and hot - things one would not necessarily want for an audio computer (maybe less a problem if you have a machine room, but ...) - I think GPUs are good at vector calculations - a bit like the CPU extensions Altivec or MMX (that was the former name ...), they get some use but if you look around and listen around in audio plugins, not everything can take advantage of that ... - MIR might take advantage of that though .... - besides doing audio processing on that audio devs could come up with some better interfaces and use the power for that ... just some thoughts ... best

[cm]

 meanwhile even mid-range grafic cards have more power than high-end computers not so long ago ...

the various vendors provide tools to actually use this processing power in applications (nVidia with CUDA, ATI with AVIVO, intel is also developing such an option) - earlier versions relied on dedicated C-programs, whereas now it seems any C++ code can be run on the GPU

 

however for MIR there is more to consider: you need to have the impulse samples *near* the processor and what gets compted is the audio from the instrument samples, so obviously a huge stream of data had to be forwarded to and returned from the GPU to the CPU ... not really a problem considering PCe x16 lanes and up to 2 GB RAM on grafic cards ... but i doubt this will be a *click-and-play* operation for a more generic programming interface.

 

using GPU power is at first hand a great chance for distributed computing (SETI and similar projects) where little data needs to be transferred but much computing power is needed, to use it for convolving several simulaneous audio streams might need some advanced programming focussing on exactly those needs.

 

note all the announcements are talking about computing power, not about data throughput, so using a GPU as an *extended effects processor* looks to be more realistic than running it as convolving engine.

our developers might give it a try though, christian

[DMJ]

Interesting points guys.

Stef, I hadn't considered the extra noise that might be created by using the GPU so much - some of those units are pretty loud. But depending on how well OpenCL offloads work from the CPU (freeing up CPU resources) it might be a worthwhile trade off considering the prices of vid cards(relatively speaking..)

cm, I see there are always more considerations to take into account then immediately apparent. Nevertheless, interesting times ahead. Imagine being able to freeze a track in a matter of a second or two, instantaneous bouncing. Thats probably something the GPU could do well 😊

There are some interesting audio related speculations in this thread

[hetoreyn]

Well .. I'll be very happy if OS 10.6 can be installed on the PPC G5 systems .. and that MIR will be universal Binary. On the other hand OS 10.6 would seem to run well on my Macbook Pro .. be interesting to see the graphics system on that be used for extra DSP .. perhaps with applying effects and such.

Hey DMJ .. you're just up the road from me .. I'm living in Burlington :P

[DMJ]

Hetoreyn, Hey neighbor :) Great site you have there by the way.

[cm]

 according to apple's announcements PPC wil not be affected by further 64bit support, therefore probably MIR can not be released as universal binary but for intel only.

christian