I have to build a workstation for processor intensive applications. I'm looking for a dual processor motherboard and a pair of CPUs to match. The rest of the components would derive from the motherboard.
Although my applications do take advantage of many cores, higher clock speeds are preferred over many cores. For example, for my purposes a 4 core @4 is better than a 6 core @2.66. And of course an 6 core @3.5 is better than a 4 core @4. You get the idea.
This is a workstation it's not mission critical so I can push the envelope a little bit. That means I'm open to watercooling and overclocking as long as the system is reasonably stable.
As for memory, 16GB is enough but would prefer a motherboard that can take 32GB.
There's a sea of combinations out there and it's not clear when a CPU can be used in dual processor motherboards or not.
I'm looking to spend less than $3K on the motherboard + 2 CPUs. That said I don't need to have the bleeding edge or anything like that. As always I'm looking for the best bang for the buck. I'm good as long as I can get a high clock count so to speak. And of course if I can get that on the cheap(er) side the better.
This other one here is the "official" workstation chip, has 8 cores/16 threads on one processor, has the highest turbo clock, but is more than twice as much as the other one, so - two of these bad boys would bust your budget, without the motherboard.
I haven't researched much about Opterons; I think they may offer more cores for a little cheaper than the Xeons on some tiers, but I think their clocks are slower all around, and the cores are probably weaker per clock than the Xeons.
I think the first one I listed is not available in box (retail) form, only "tray".