Mine is 2GHz
Maybe it just a driver issue and not a CPU bottleneck. We have to wait for 10.6.5 (or maybe you should try to get 2010's ATI video driver... since those systems run a newer build of 10.6.4 with updated video drivers)
There are no discs in the box, but I am still on 10.6.4 and I am running OS X Server (dunno if that matters) and 6GB of memory.
Thanks for the info