Like the title says, I'm looking to install a 64 bit version of XP or Vista on my 2007 model octa-core Mac Pro. I've done some searching and it looks like there are some issues with the pre-2008 models regarding 64 bit support. What's the deal with this? I'm currently running 32 bit XP pro in boot camp and it's not cutting it. I use Solidworks pretty heavily and I've been hitting 'out of memory' messages as well as painfully slow rebuilds when working with a lot of features.