Can't make my mind up between having:
Dual Xeon's at 1.8GHz (Nehelem architecture, no Hyperthreading), so 8 real cores total.
Or just a single i7 950 at 3.06GHz, so 4 real cores and 4 virtual cores.
What do you guys think?
Our CPU loading isn't expected to be that high but it will probably end up running about 10 or 12 VM's eventually. It will have 24GB memory.
I'd go with the dual Xeons.
Today the 8x1.8Ghz will be slower than the 4+HTx3Ghz i7 for purely computation tasks - BUT the memory bandwidth for the dual Xeons will be higher and in the future you can easily swap out the Xeons for ones with HT or higher frequencies when they drop in price, this may coincide with an overall increase in system load too.
The other thing to consider is that with dual Xeons you can do 24GB via 6 x cheaper 4GB DIMMs, to do the same for an i7 will require 3 x much more expensive 8GB DIMMs, plus you'll have lots of spare slots open on the xeons if you want to upgrade in the future, you'll have less on the i7.
Edit - do you HAVE to use Hyper-V? ESXi is equally free but you're likely to get a lot more VMs into the same memory.
i7. The xenones aer totally underpowered if you ask me. Most important is MEMORY. TONS of memory - at least the possibilty to upgrade. 32, 64gb. And LOTS of discs. I hope you plan many discs.
When my first bigger host started it had a Raid 10 of 4 velociraptor and 32gb RAM. Not it has 6 raptors (soon 8 or 10) and 64gb RAM. Discs make or brak many things - like patching ;)
I agree with TomTom regarding the memory requirements. 24GB will be insufficient to host 10 virtual machines unless they happen to be very limited in functionality. We just purchased a Hyper-V server and loaded it wtih 96GB of RAM in anticipation of running 10 to 15 virtual machines. As for the CPUs, real cores are always better than virtual cores, but the 1.8GHz Xeons are on the rather slow side making it a tough call. If you can manage to get a pair of 2.4 to 2.6GHz Xeons, that would make the choice much easier.
