According to the Asus Rampage V Extreme support page, my R5E mobo is compatible with some Xeon procs.
I have an opportunity to trade my "above average" i7-5960X straight up for either an E5-1680-3 or an E5-2667-3, or for an extra $1000 I can trade up to a E5-2687W-3. (Current local $CDN prices are shown below just for comparison, all my trade options seem highly profitable - the IT guys at work have spoken.)
Core i7-5960X - 22nm Haswell-E, 8 Cores+HT, 3.0GHz-3.5GHz (3/3/3/3/3/3/5/5 Turbo), 8x256KB L2, 20MB L3, 4xDDR4-1333/1600/2133 (64GB), 40xPCIE3.0, 5GT/s DMI2.0, 140W, $1450 - current proc - fully stable 4.6GHz@1.3V on air
Xeon E5-1680-3 - 22nm Haswell-EP, 8 Cores+HT, 3.2GHz-3.8GHz (3/3/3/3/3/4/6/6 Turbo), 8x256KB L2, 20MB L3, 4xDDR4-1333/1600/1866/2133 (768GB), 40xPCIE3.0, 5GT/s DMI2.0, 140W, $2470
Xeon E5-2667-3 - 22nm Haswell-EP, 8 Cores+HT, 3.2GHz-3.6GHz (2/2/2/2/2/2/4/4 Turbo), 8x256KB L2, 20MB L3, 4x3xDDR4-1600/1866/2133 (768GB), 40xPCIE3.0, 5GT/s DMI2.0, 2x9.6GT/s QPI1.1, 135W, $2525 - not on official processor compatibility list
Xeon E5-2687W-3 - 22nm Haswell-EP, 10 Cores+HT, 3.1GHz-3.5GHz (1/1/1/1/1/1/1/2/4/4 Turbo), 10x256KB L2, 25MB L3, 2x2x3xDDR4-1600/1866/2133 (768GB), 40xPCIE3.0, 5GT/s DMI2.0, 2x9.6GT/s QPI1.1, 160W, $3000
I admit that I've never run a modern Xeon platform. But my rig isn't really used for gaming <sigh, it was never really used for gaming> and I can indeed leverage mega multithreaded madness.
I notice that these two 8-core Xeons appear superior to this 8-core i7 (indeed, I suspect they might even be different bins/packaging of otherwise identical parts). Unless I'm missing something important?
The E5-16xx part is a "1S Uni-processor", the E5-26xx parts are "2S Dual-/Multi-processor" - does this mean anything at all on my single-socket single-processor X99 mobo?
I'm guessing QPI specs won't have any impact on compatibility/performance with my X99 chipset (which links to the proc through 5GT/s DMI2.0)?
I obviously won't be using more than 64GB, the maximum my mobo supports (although there are a few X99 mobos out there which will support 128GB or 256GB, when 16GB and 32GB DDR4 UDIMMs become available). But I suspect the generally beefier capabilities of the integrated memory controllers in the costly Xeon procs might tolerate larger and faster memory configurations.
The R5E offers advanced/extreme tweaking options and fine control over voltages and timings. If Xeons can overclock well (and I suspect they generally can't) then it will be on a mobo like this one. I don't know if the Asus's proprietary LGA2011-3 OC Socket will have any effect, but it should be completely compatible - I can disable the extra OC Socket capabilities.
I don't expect any compatibility issues with my CPU cooler, chassis, PSU, etc. I don't expect any legal complications. (My IT guys work with a mix of Dell, HP, IBM/Lenovo, and Supermicro equipment, if that matters.)
Somebody informed me that Intel locks out Xeon CPUs in microcode as the platforms age ... I have no idea what this means, but if true then it sounds worrisome.
Is this a good trade or bad trade? Am I just asking for a ton of Xeon problems?