I was poking around the Apple website reading about the new features of their latest OS, OS 10.4 "Tiger". With the release of "Tiger", Apple has included an update to Xgrid, a feature that appears to be somewhat hush-hush. Actually, it appears to have been around since last January but just isn't mentioned much.

Xgrid allows OS X-based computers to be combined into a cluster (similar to a Linux "Beowulf" cluster). This lets their "Wonder-Twin powers combine" (anyone get the joke? :-)), creating a supercomputer in minutes.

Unfortunantly, the apps have to be Xgrid-enabled, just like Beowulf. Xgrid is good for programs that can be broken up is smaller pieces independent of each other, the best examples being Monte Carlo-type calculations, parameter studies (a program rerun several times w/ different parameters), fractal generators, and graphics rendering such as POVray. Doing some searches I've found that some of the Adobe products might be enabled for Xgrid, such as After Effects, and there's supposed to be a workaround for Maya.

Basically, if you create custom programs that can be broken down into independent sections, Xgrid might be a benefit. Right now games won't benefit too much because most of the overhead is in the graphics and I/O, not CPU intensive work. However, I'm guessing that as more people buy Mac Mini's and other Apple gear, more "shrink-wrapped" applications will be Xgrid-enabled.

Here's some links for anyone interested:
Apple's main Xgrid page
Apple's OS X Server page discussing Xgrid
A site giving a practical intro to Xgrid and gives an example using POVray.
Apple's Developer site discussing how it works
University of Utah's Student Computing Labs page