OK, I've been living with this HP server for about 3 months now. I'm still loving it - it's stable, quiet, and powerful. But I've finally decided I should have bumped up the processors a bit. I've got a pair of 5130 Xeon processors in here. They're dual core, and they are more than powerful enough for anything I'd normally do on this box if I had the "typical" 8GB of RAM. And they're a cost effective choice. But I spec'd this box with 16 GB of RAM, giving me the ability to load twice as many Virtual Machines as the 8GB would have given me. And when I get past about 12 GB worth of VMs loaded up, I start to feel the whole thing slow down a bit. Now some of that is disk access - even with 8x72 GB, 15k SAS drives in here that's a lot of disk activity - but it's also just a lot of processing being done. I've got at least 5 instances of Longhorn Server running, plus multiple clients. And when I get everything busy I can notice it a bit. Not enough to be an issue, but enough to notice. I'd have probably been smart to have gone with a pair of 5260 Xeons. Normally, I'm not a big fan of the current Intel implementation of quad-core. And given the memory limitations still present in the Xeon, it might still be an issue when this thing is loaded up, of course, but overall I suspect the extra cores would help.
If it sounds like I'm complaining - that is most definitely not the case. This is still a great little server and I'm really happy to have it! As a writer, working on multiple projects at once, it is a huge luxury to have a server of this quality. It makes everything so much easier. And I can't wait to load it up even more when we finally get a new build of Centro. At which point I will have to switch from Virtual Server to something else, most likely VMWare Workstation. I'm not looking forward to that, mostly because I've got a lot of configuration invested in Virtual Server. But I need 64bit guest support, and Microsoft's Windows Virtualization (Viridian) is just running too late to wait, sadly.