Hi, I have 2 x Sapphire HD6870 1gb GPU's & a CM650Watt PSU, if the system is set to non Xfire mode I have no issues but as soon as I put it in Xfire Mode, The screen erratically goes black. Is this a power problem......?????
It could be you should give a little more detail. When did this problem start occuring. Are you sure you have installed your cards and drivers correctly? How old is the system and more specifically your PSU? How many watts does your system require and have u used a WATT calculator to check and see if you have enough watts? Are you doing any overclocking? Im sure its possible to run 2 cards with a 650 watt supply, but depending on what else you have on your computer and if your overclocking, you probably dont have much buffer room for power if any. Thus, this could result in the cards running but not being stable. I had a similat situation Im running 6950 in CF and sometimes my cards would be unstable it seemed. On some occasions it would do exactly what you explained. I was using an older 1000W PSU. I replaced it and haven't been having any problems since. All and all I would say it probably is a power problem, but to be sure we need more details.