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+--- Thread: Barebone with 8 GTX 690 (/thread-2425.html)
Barebone with 8 GTX 690 - zarabatana - 07-04-2013
If is possible one barebone with 8 GTX 690 (dual GPU), why can't use 8 7990 ?
https://www.facebook.com/media/set/?set=a.592510024104402.1073741828.126508714037871&type=3
RE: Barebone with 8 GTX 690 - epixoip - 07-04-2013
nvidia driver supports 16 devices, fglrx supports only 8.
GTX 690 draws less than 300W, 7990 draws 375W. the power supplies in that chassis supply 2400W of power @ 240V, and only 2000W @ 120V. so 8x 690s is cutting it really close power-wise, especially considering you have two 130W cpus installed, and those 120mm fans draw 225W as well (each set of 2 draws 75W.) you can probably modify the power backplane so that it uses all three psu instead of 2+1; that would give you 3000W of power, but even then, that's still cutting it close for the 690s, and still not enough for the 7990s.
RE: Barebone with 8 GTX 690 - zarabatana - 07-05-2013
Thank you very much for your explanation and for your fast replay!
RE: Barebone with 8 GTX 690 - tatgdi - 07-05-2013
(07-04-2013, 11:37 PM)epixoip Wrote: nvidia driver supports 16 devices, fglrx supports only 8.
GTX 690 draws less than 300W, 7990 draws 375W. the power supplies in that chassis supply 2400W of power @ 240V, and only 2000W @ 120V. so 8x 690s is cutting it really close power-wise, especially considering you have two 130W cpus installed, and those 120mm fans draw 225W as well (each set of 2 draws 75W.) you can probably modify the power backplane so that it uses all three psu instead of 2+1; that would give you 3000W of power, but even then, that's still cutting it close for the 690s, and still not enough for the 7990s.
What's involved with getting 3000W of power out of this unit? Is it an actual feature of the FT77? And the 3000W was assuming 120v input; I imagine.
RE: Barebone with 8 GTX 690 - epixoip - 07-05-2013
no, it's not a feature. you would need to hack up the power backplane. i have seen some people doing this, but i don't know how they did it. and even if you were successful in doing it, i'm not sure i'd trust it to handle 3kW+ of power.
yes, 3000W would be at 120V. at 240V it would be 3600W. but even then that's not enough, because 3600W @ 91% efficiency = 3276W
8x 7990 = 3000W
2x Xeon = 260W
6x Fans = 225W
so 3485W required for GPUs, CPUs, and case fans alone, and that's not counting the draw for the motherboard, memory, and hard disk(s), but the psus would only be able to reliably deliver 3276W