I have been trying for a while to get 5 or 6 cards working on my motherboards, and I haven't been able to get more than 4 cards being recognized correctly by Windows at a time.
I have tried with 2 different motherboards:
1- MSI Z77A-GD65, with a CPU Intel Celeron G1620.
This motherboard has 7 PCIe slots (3 x 16X and 4 x 1X).
2- Gigabyte GA-Z77X-D3H, with a Intel Celeron G1620.
This board has 6 PCIe slots (3 x 16X and 3 x 1X)
With both those motherboards, I couldn't get Windows to recognize correctly more than 4 cards at a time. Whenever I plugged 1 (or 2) more card, 1 (or 2) of the cards would get the error "Windows has stopped this device because it has reported problems. (Code 43)" (as seen in Device Manager). I tried for many hours, tried different slots combinations, etc. - couldn't make it to work.
I used powered risers too (16X and 1X).
I have seen many posts where people talks about rigs of 5 or 6 cards (or even more), even on Windows, so I am pretty sure it can be done.
There even is a forum post here where pug writes that he has a rig with the same motherboard I have (Gigabyte GA-Z77X-D3H) with 6 cards on it:https://forum.litecoin.net/index.php/topic,1395.msg8709.html#msg8709
My question is: How??
Can those whom have managed to get 5 or 6 cards working on a rig give us some details about how they did it?
Which hardware did you use?
Are there any special tricks that have helped you? E.g. changing some settings in the BIOS, shorting pins on the PCIe slots, using dummy plugs, specific drivers version, or else?
I used Windows 7 Ultimate 64-bit, 8 GB RAM, dual PSU (1050W each), with AMD SDK v2.8 64-bit and drivers v12.8 64-bit. (cgminer / reaper is not relevant here, I need to get the OS to see the cards properly first)
Many thanks to any info around that!