C60x is for dual Xeon (Ivy/Sandy-E) CPU support.
C60x for dual boards only? Think that is not the case For example, look at this: http://www.supermicr.../c600/x9sra.cfm
Also still undecided between Dual CPU setup (lower corecount, higher clock) and a single CPU (both high core dount and clock impossible!)
What I would like to know is how big the performance penalty with OS X and multiple CPUs really is. Would it be enough to offset a 500MHz difference in base clock? (based on the E5-2637v2 vs one E5-1680v2 example)
Yeah, know his blog (and glad he answered to me), also thought that the new Board he mentioned (GA7-PESH3) could be a candidate for my needs. So if I understand this right, LGA2011 support is not quite complete, but improving and expected to be fully working with the release of 10.9 - right?
For a workstation i'd say use a Ivy-E Xeon with the most cores you can buy (and your chosen motherboard can support), paired with the maximum ECC RAM you can afford (the problem is, it can end up being almost as pricey as a MacPro). I wouldn't use an overclocked system when uptime and stability are as important as performance, but that's me. If you go I7 because of budget constraints, buy Ivy-E instead of Sandy-E. With an I7 you'll have the option of overclocking the CPU, which is not an option with Xeon processors.
Yeah, that is what I thought first: 8 core Single XEON CPU _or_ 2x4 / 2x6 Cores Dual XEON CPU.
Since I want stability, I do not want to overclock at all costs.
Least but not last - and i know Rampage will not agree with me, but whatever - consider buying the newest high-end graphics solution from AMD: Apple is going FirePro for the MacPro, and it's very likely many apps - and perhaps OSX itself - will rely heavily on OpenCL, where nVidia's performance, Titan included, is a joke. If you have already a workflow with applications that are CUDA dependent, though, go for a GTX 7xx series card.
GPGPU would be mostly needed for After Effects, Premiere and Blender.
At least AE and PR should do better with CUDA, right?
Plus: I do not like AMD in general - got quite some probs with this brand in the past.
Edit 1: and also I thought that the NVIDIA Driver support was better - at least they post their own drivers whereas I could not find any OS X drivers on the AMD page.
C60x is for dual Xeon (Ivy/Sandy-E) CPU support. Since X79 supports Sandy-E and Ivy-E CPUs, including but not limited to Xeon CPUs, and since Apple won't release a dual CPU version of its new MacPro, perhaps Rampage thinks a C60x is overkill and will be harder to support properly, and i tend to agree.
Well but the C602 chipset is what the new Mac Pro apparently uses. And they must support Dual CPUs, at least with a single socket motherboard. (The new 12 core Ivy Bridge E is actually a Dual CPU). Also, the E5-1680v2 I have my eyes on seems to be in one of the new Mac Pro configs.
So I am not so sure about this Point!