itou31 wrote:Hi Tutor,
Need your advice also :
I will get a X8DTH-IF with 2 X5570 for a spare rig. the slot are 8x speed but in 16x format. I think to put 6 GPU later on the board and add 4 other on the amfeltec splitter on the last slot. The BIOS seems to not have 4G decoding. Do you think that I will get out of ressources ? with my main rig (a 3930K in asus P9X79) I can manage only 9 GPUs.
Thanks
What OS do you intend to run on it? The response in the next paragraph assumes the answer = Windows. If the answer = Linux, then the response would be that getting 9-10 GPUs working wouldn't be at all unlikely. Under Linux, I've gotten 16 GPU processors (8 x GTX 590s) working on my Westmere supported Tyan, but it's manufacturer intended GPU processor limit is 8 and under Windows the system with that same load wouldn't boot completely. Moreover, I just stopped at 16 GPU processors. It might be able to go higher. Under Windows, 9 GPU processors (originally I had thought it was 8 because I had been using GTX 590s and Titan Zs for testing) is the max. for that system. Always keep in mind that different GPU models have different IO space requirements and that, as a general rule and trend, the newer the GPU family, the more IO space they need [they tend to have more functionality to account for than do their predecessors]. Thus, factors such as these also affect the cap.
Few Nehalem/Westmere (i.e., for Intel 5500/5600 series CPU) motherboards have an above 4G decoding selection. GPU computing wasn’t very prevalent back then. Thus, one’s rolling dice/speculating whether someone can get 2 or 3 or 4 or more GPUs [beyond the number of PCIe slots] to work in such systems (usually adding 1 additional GPU [beyond the number of PCIe slots] is possible on almost any Nehalem/Westmere supported motherboard regardless of OS). The one thing that you’d have in your favor is that Supermicro systems generally have very well developed bioses and it’s been my experience that Supermicro will make the effort to optimize the bios further upon customer request. However, the board you reference is sort of ancient now and I’m guessing that you’re not the first owner. Thus, unless it’s a gift or a crazily low priced deal, I recommend that you explore motherboards that support Intel’s next gen or higher processors (Sandy/then Ivy bridge/then Haswell/then Broadwel/then Skylake - latest)*/ and consider searching for suitable CPUs on Ebay, where I’ve found great bargains. That’s what I'd do particularly if I wanted to install 10 or more GPUs processor in a system wit minimal hassle.
*/ I routinely search Intel’s site -
http://ark.intel.com - where I can read the specs for any CPUs that I’m interest in, looking particularly for (1) PCI Express Rev., (2) Max # of PCI Express Lanes supported, (3) Max CPU Config., (4) Memory Spec., (5) Core #/Threads # and of course speeds/frequencies. Also, I always download and read manuals (paying particular attention to board pics and schematics) before any motherboard purchase, looking particularly for, among others, “above 4g” functionality and slot count (& if >1 CPU - lane sourcing), slot blockers (like unsound memory slot placement) and lane type.
P.S.
Irony #1. My having similar concerns/issues with a pre-Sandybridge motherboard is why this thread was created. So, I understand your concerns.
Irony #2. Those concerns/issues have further led to me warping my mind more than I could ever have originally guessed.
Because I have 180+ GPU processers in 16 tweaked/multiOS systems - Character limit prevents detailed stats.
...it will be aircooled 
