MSI 990FXA-GD65 and Sapphire 7870 XT Tahiti - only 4 cards working

[wojgp]

Hi
I am trying to get more than 4 GPU working with 990FXA-GD65 and Sapphire 7870XT Tahiti, but every 5th card get error
I shorten pins in all PCI-E x1 sockets on motherboard, except x16 sockets. I use win64-bit , Sempron X2 190 cpu and 2GB RAM
Please help

http://gsm-support.net/download/msi/screenshot.jpg

In another PC with the same mobo I use 3 x Sapphire 7870 XT Tahiti + 1 x HD6990 and all 5 GPUs are workable.

[malevolent]

What drivers and SDK combination are you using? Are they the same ones as in your other rig that is working fine with 5 GPUs?

Some driver versions won't let you run with more than 4 GPUs.

[wojgp]

I use ATI 13.1 same as in another rig-without SDK , becuase I use it for sha1 algo. I've just tried to connect powered riser to one of cards, but it is the same.
Is there any sense to shorten pins in 16x slots if I connect them with card using 16x-16x riser ?
The last thing I could try is to use all powered risers.
Do You have any other ideas ?
Thanks.

[crazyates]

32 or 64 bit windows?

[wojgp]

Win7 64-bit ultimate
Just connected 2nd powered riser, result is the same

[anderl]

Win7 64-bit ultimate
Just connected 2nd powered riser, result is the same

Go Windows 8.  I had the same problem with Win7 and 5 cards.

[wojgp]

Thanks. Could You recommend any other mobo which will allow to work with 6 GPUs ? Prefered MSI Any CPU , but I hope not MSI Bing Bang X-Power II

[Zanatos666]

Read this today. Maybe this would work.

https://bitcointalk.org/index.php?topic=257486.0