Howard Oakley
Snow Leopard’s OpenCL can put blisteringly fast GPUs to good use, but finding one that works with your Mac Pro isn’t as easy as it should be.
Most of Apple’s product names have been chosen carefully to inform rather than bedazzle: the Pro is aimed squarely at professionals, MacBooks are almost as portable as books, and the mini is, well, mini. If only sub-system suppliers were as informative and helpful.
Although you know better, it could be a good guess that a GeForce GT 120 was a sleek superbike or the latest weaponry used in Afghanistan. I suspect that graphics cards are named to appeal to fanatic game players, in quest of bigger and more vivid effects in Need for Speed or Call of Duty. If Apple gets its way, this could change.
We were told that Snow Leopard would be able to harness new blisteringly quick graphics processing units (GPUs) to augment a Mac’s total processing power using OpenCL. Although a splendid idea, using co-processors to boost performance has a chequered history: recall the dead end reached by Apple in its Quadra models with digital signal processing (DSP), and the saga over exploitation of Motorola 68K-series math co-processors such as the 68881. In both cases, the hardware looked sexy, performed impressively under test, but few software products made good use of them.
GPUs are potentially very powerful, in specialist tasks comfortably outperforming general-purpose processors. OpenCL looks good, and has the support of good developer tools. But before they can succeed, there needs to be a critical mass of Mac users with OpenCL-capable Macs. Currently, this is limited to models with one of 10 Nvidia graphics cards or one of two ATI cards. This excludes MacBook Pros made before June 2007, the early MacBook Air, non-unibody MacBooks, minis and iMacs prior to March 2009, and most Mac Pros, including my original-series eight-core.
When I ordered my eight-core, the Nvidia GeForce 8800 GT wasn’t readily available, so I had to settle for the 7300 GT unless I was prepared to wait and stump up the considerable premium for the card. With the new promise of OpenCL ringing in my mind, I tracked down a reasonably priced GeForce 8800 GT for the Mac Pro just after Snow Leopard was launched. The incentive was now strong to add this finishing touch to a system that should reach new peaks under Snow Leopard. Sadly, the box that arrived contained the right card, but the wrong version: a tiny label on it gave the Apple part number 630-9897, which turns out to be for the Mac Pro (Early 2008). That for the Mac Pro (Original) is 630-9492, but I’m unsure whether that will work in an original eight-core, a model not mentioned in Apple’s explanatory article at support.apple.com/kb/HT2848.
I’ve castigated Apple here before over using multiple part numbers for items (my useless GeForce 8800 GT bears no fewer than three different numbers), and for using near-identical descriptions for different parts. Nowhere on the card’s box does it state for which model it’s intended, and it’s downright confusing that Apple has different variants for different Mac Pros.
So if you have a Mac Pro (Early 2008) and have ended up with an unusable Nvidia GeForce 8800 GT card intended for an original Mac Pro, drop me an email. I just hope OpenCL will attain critical mass and not get buried in a grave alongside the Quadra AV.
