The latest edition of the Top500 supercomputer rankings has been posted, and two Mac systems have made the list this time around.

Generally, supercomputers aren't something you associate with Apple hardware. Row after row of big, lumbering clusters of faceless black towers locked away in a windowless gray room somewhere is pretty much the antithesis of what Macs are all about.

Aside from that, there's the fact that most supercomputers are made for something a bit different than Garage Band or Photoshop. These puppies are usually aimed at performing massive amounts of computational activity and as such are usually loaded with specialized, often proprietary operating systems made to carry out a fairly limited range of activities.

Still, these two outfits managed to push their Apple hardware into the upper echelon of the computing world. Though Intel claimed a whopping 75 per cent of the list with its chips, both of these systems were made before Apple's switch, so they both rely on dual-core G5 processors.

Ranking 141 on the list was a custom system from computing services firm COLSA. The massive cluster of XServe was originally built to model hypersonic flight. It runs at around 16 teraflops, though it has peaked at as many as 24.58 teraflops.

It has also withstood the test of time, remaining in the top 500 for three years. When the COLSA system debuted, it ranked 15 on the list.

A little further down the list is the Virginia Tech "System X" cluster. Originally made from 1,100 G5 towers, the system was later converted into XServe units. Even older than COLSA, System X is now going on four years old. In 2004, the system made its debut on the list at #7.