motherboard not enough bandwidth?

[tac12345]

hello, first post !

i just bought 2 X ati 6770 for mining to replace my old 4850

but it seems that my bandwidth isn't enough. when i mine with only 1 gpu, i have +- 10 Mhash.

when i mint with the 2nd card at the same time, the forst card will reduce it's performanfce, and the 2nd will be around 20 Mhash.

overall they never mine at their full potential...


any idea what could be the cause? i checked my bios, the only thing i could do is to force the 2nd pci-e to 4x (it disable 2 other pcie 1x),



thanks in advance!

[1713481668]

1713481668

[SaintDevil]

Are you running them in crossfire?

[tac12345]

no

[SaintDevil]

no

It may be the mining software, what mining program do you use and what settings?
Also do they have absolutely same mhz in msi afterburner or any other program that can show it?

[kwoody]

Doubt this is the problem, but... are you sure you're mining with the 2 cards as seperate devices? device=0 and device=1 respectively? What you're describing sounds similar to 2 instances of mining software trying to use the same card. One instance of the software will use most of the card, the other instance using the rest, etc

[tac12345]

but... are you sure you're mining with the 2 cards as seperate devices? device=0 and device=1 respectively? What you're describing sounds similar to 2 instances of mining software trying to use the same card. One instance of the software will use most of the card, the other instance using the rest, etc

i fail SO hard LOL

thanks for pointing this !
newbie error i guess... i should have paid more attention to this detail.

back in business now !