Pairing up video cards from different companies

[azrael]

I currently have an EVGA 8800 gt 512 card in my system and am looking to add a second card so I can run sli. I've been having trouble finding another EVGA card at a price I'm willing to pay. I understand that pairing up cards made by the same company is the ideal way to go, but would it be a big problem if I bought say a PNY or XFX card for my sli setup?

 

[jitpublisher]

Does not matter.