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Matthew Attoe · May 12, 2009, 06:15 AM

Hi,

With all the talk about Snow Leopard harnessing the GPUs of machines for additional processing power, I was wondering if I put in an additional video card (not hooked up to a display) would this additional GPU be taken advantage of?

Basically, I have an 8800GT in my Mac Pro and the original ATI 2600 now sitting redundant in the box. I also plan to shove in one of the new GTX285 cards when they are released in place of the 8800GT, hence wondering about using an additional GPU as well (obviously keeping within the 300watts limit).

I hope I've made sense

As always, any advice would be much appreciated.

Matthew

Matthew Attoe · May 13, 2009, 06:07 AM

Oh well - thanks for looking anyway

Big Mac · May 13, 2009, 06:15 AM

I don't think OpenCL will work across multiple GPUs, at least not initially. Apple is behind when it comes to utilizing multiple GPUs.

OreoCookie · May 13, 2009, 07:06 AM

More importantly: only a few apps are taking advantage of gpus as a way to augment cpus (Color, Motion and Aperture come to mind). Grand Central and OpenCL will make it easier to make use of GPUs, but you'd still have to wait for apps to take advantage of it.

You don't need to be a clairvoyant to assume that Apple's own apps (Final Cut Studio, Aperture, etc.) will be the first (the current version of Final Cut uses Carbon so they'd have to put in some work anyway). But beyond that I'd wait till the apps you want to use actually support Grand Central (upgrade when you need it).

cgc · May 13, 2009, 08:14 AM

Originally Posted by Matthew Attoe

Oh well - thanks for looking anyway

You give people 24 horus to reply before you give up? There's a lot of posts to reply to...every post gets a reply eventually...

How prevalent is nVidia's CUDA on Windows? I've seen it in Windows transcoding programs and distributed ocmputer (e.g. BOINC) projects, but not much else. It'd be nice if it was easier to use the GPUs in SL, maybe that would increase its use in similr Mac programs (e.g. Handbrake, Quicktime, etc.).

Salty · May 13, 2009, 01:39 PM

I imagine apps like Handbrake will include it, perhaps we'll eventually see Adobe start taking advantage of it. And I imagine Apple will put support for it into their pro machines. I'm unsure if they would in iLife given the fact that iMovie et al are really targeted at the non dual GPU machines.

Matthew Attoe · May 14, 2009, 06:04 AM

Originally Posted by cgc

You give people 24 horus to reply before you give up? There's a lot of posts to reply to...every post gets a reply eventually...

How prevalent is nVidia's CUDA on Windows? I've seen it in Windows transcoding programs and distributed ocmputer (e.g. BOINC) projects, but not much else. It'd be nice if it was easier to use the GPUs in SL, maybe that would increase its use in similr Mac programs (e.g. Handbrake, Quicktime, etc.).

Sorry cgc,

Didn't mean to come across as impatient or ungrateful

Thanks for all the replies though - maybe I'll hang on to the extra video cards and see what happens and then what extra cards will work etc

Matthew

angelmb · May 14, 2009, 12:26 PM

Originally Posted by Salty

perhaps we'll eventually see Adobe start taking advantage of it.

and… you'll have to pay more for the required app upgrade itself than any additional GPU

mduell · May 26, 2009, 05:33 AM

Originally Posted by Big Mac

I don't think OpenCL will work across multiple GPUs, at least not initially. Apple is behind when it comes to utilizing multiple GPUs.

Do you have a source on that? I didn't have any idea Apple was that far behind in their GPGPU development. Obviously very late in release and limited in initial userbase (compared to CUDA or even DX11C), but I had naively assumed they would be on-par with the established players as far as features (like multiple GPU support) when the release did come since it's a major part of SL.

Originally Posted by cgc

How prevalent is nVidia's CUDA on Windows? I've seen it in Windows transcoding programs and distributed ocmputer (e.g. BOINC) projects, but not much else.

It's quite popular in fields that can make good use of it (scientific and corporate modeling and simulation). There's a MATLAB (popular numerical computing/4GL package) add-on that automatically converts MATLAB M-code to CUDA. The official website has an extensive list of applications.