07-04-2013, 11:37 PM
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.
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.