I'm curious, why is it not possible to buy pre-configured, off-the-shelf dual or quad CPU PC systems?
I know that you can get dual CPU server motherboards and build your own system, but as far as I know no one sells a pre-built desktop system that looks anything like the Mac Pro (spec-wise).
EDIT: Looks like I was mistaken. You can get high-end PC workstations.
Take the Dell Precision T5500. Google it (to get the crazy long Dell configuration page URL) and you can configure it with dual six-core Xeons, for example.
A quad core Dell is half the price of a 12-core Mac. Once you put the same CPU, RAM, and hard drive in the Dell, the difference is about $200. It's cheaper, but not that much cheaper. The bulk of a Mac Pro's cost is really just passing along Intel's price for Xeon processors.
It is perfectly possible. You buy them from companies that supply the professional CAD market and it is relatively easy to find 32 core, dual processor, twin graphics card systems for less than $5000.
The 8 core DP Xeons weren't out yet when that review took place, but the Sandy Bridge chip was a big improvement over Westmere, in addition to the extra cores.
I'm not sure it's such a slam dunk -- a brief scan of the virtual machine benchmark didn't seem to have a more heavily concurrent load. Plus the Opterons are substantially cheaper.
If I was building a server I'd probably look at the Intel parts, the cost/performance curve is justifiable. But my personal case right now is running lots of test VMs simultaneously on a workstation, the Opterons are more attractive.
I should probably have linked to Sandy Bridge EP vs Bulldozer, which is much more lopsided. The 6C holds its own nearly everywhere, with comparable price and much lower power usage, and there's always the option of bumping up to 8C when needed:
I don't mean 12 core, I mean 32 core. AMD is selling 16 core CPUs. And the Mac Pro is not a dual CPU, 32 core, twin graphics card machine, which is what I described.
I know that you can get dual CPU server motherboards and build your own system, but as far as I know no one sells a pre-built desktop system that looks anything like the Mac Pro (spec-wise).
EDIT: Looks like I was mistaken. You can get high-end PC workstations.