Quote from: djm34 on March 01, 2014, 07:37:12 PM

Quote from: Banin on March 01, 2014, 07:22:03 PM

Quote from: rahrahrah on March 01, 2014, 07:04:38 PM

Quote from: djm34 on March 01, 2014, 06:47:47 PM

The bandwidth will also vary depending on the number of installed card.
My motherboard (Z77 G45), will allow one card to run at 16x bandwidth (pcie 3)
but 2 cards will run at 8x bandwidth
3 cards (using the pci-e 2.0) will make the first cards run at 8x bandwidth and the two other at 4x

What tool do you use to confirm this slow down?

I got this one my MB manual Wink

me too.
However, hwinfo64 show the actual bandwidth used by the card (gpu-z also I think)

I'm now using two 750 TI's on a motherboard with PCIe 1.0, one is sitting on a x16 slot, the other one on a x4 slot (IIRC, the equivalent of a PCIe 3.0 x1 slot), I have no bottleneck if I run all my mining with '-H 2'. I'm reaching the same speeds as everyone else here, roughly 310 to 320 kh/s scrypt or 160 mh/s kekkak with moderate overclocking. Without the '-H 2', I go straight to 250 kh/s or so in scrypt.

(hash rates quoted are for a single card, and both reach the same figures with -H 2)

Cheers,
Myagui

Edit: Will check & report on my bus usage tonight.