Will your HP DL380 G6 do this?
That's why they are still willing to pay a premium for the boards..
No, but since I've got twice the threads and twice the memory channels I would think we'd probably still be pretty even on horsepower when it comes down to it.
I think my point may have been missed. If you have an X58 board, picking up one of these Xeon's is a no brainer, it's an unbelievable bargain regardless if you're overclocking. I'm completely on board with that.
The boards on the other hand are going for higher than new prices (some look to be close to double their original price) and lack features like good SATA3/USB3 that you can get on a new board that's half the price or less.
Don't get me wrong the amount of overclocking potential is impressive. But at stock clocks a 5820K will obliterate an X5690 from everything I see. How much of an overclock do you need on one of these to match a Haswell-E and how much power are you using at that point? Again, serious question, not trying to sound like a dick.
That brings me to, if you're doing something that benefits from eeking out every last bit of power (rendering, etc), then power per watt has to enter into the equation. Especially if you're doing this for business purposes. I used to have a DL580G5 (4x Xeon x7460's, 2.66Ghz 6 cores). But that system used about 1,000 watts constant. I replaced that with the previously mentioned DL380G6 that pulls 145w. That's a $70/mo difference at $0.10/kwh. That adds up pretty quickly.
Again, not arguing the value of the processor. Questioning the wisdom of spending that kind of money on an outdated motherboard.