there are so many brands for gpu right ? brands i mean is not nvidia or ATI but i mean like asus, evga, gigabyte, msi, sapphire and etc. so what is the best brand because i want to buy HD7850 for my new pc, thanks.
As for AMD/ATI cards I have found Sapphire to have the best cards out there. I still have several cards running in PC and not one of them have failed me. I have a 3850(agp) 4850 5850 6950 and a 7950 all running in mine and friends PC's even the oldest 3850(agp) is still used every day. I use MSI for there motherboards but I went though 2 MSI 6950 cards in less than a month before I went back to Sapphire and have never had a problem with it since.
much like bryon I have had many sapphire cards and my experience has also been pretty good.... that was until one finally died and I had to deal with their warranty...
took me well over 2 months to get my card back from the point I sent it(which they made me pay for)
For AMDs, I'd say Sapphire is top on my list. They do have the reputation. Other AMD manufacturers that are also top notch are ASUS, MSI, and XFX. I'd also toss in Gigabyte into the mix, their GPUs are as solid as their motherboards.