Hi, I am building my first gaming rig and have so far gotten most of my parts except my graphics card and maybe a ssd/hdd.
I am not sure which graphics card to buy. I was looking at a Radeon 7870 or Gtx 660. I heard the Radeon 7870 was faster than the 660 but was also looking into a Ti version. I know they are a little more expensive but I wasn't sure if it was worth the extra cash. If there is a card that is better or certain Sli / Crossfire configurations that would be better please let me now. I'm not really worried about power heat etc. I'm just interested in performance and price. I also would like to know if there are any reasons why I should go with Amd over Nvidia or vice versa.
A higher bit doesn't necessarily mean faster GPU. It's true that the memory will run faster, but that's not the whole story. Just an example, a Radeon 7850 (256bit DDR5) is still slower compared to GTX 660 Ti.
That said, a GTX 660 Ti has about the same performance with the Radeon 7870 (http://www.anandtech.com/bench/Product/548?vs=647). It's just a matter of price and preference. Power consumption wise, the GTX 660 Ti consumes lot less power than the Radeon 7870, and it has PhysX and CUDA. On the other hand, the Radeon 7870 has a great GPGPU capabilities compared to the GTX.
My thoughts -- if I'm playing at a resolution of 1920x1200 or below, I'll go with the GTX. If above, the 7870.
+edit -- and processor speed isn't anything either. My GTX 560 Ti runs at 822MHz, and yet it's still slower compared to the 576MHz GTX 295. The number of cores and architecture type also counts. For example, a Pentium 4 3.0GHz is slower than an ultrabook's Core i5, even when it runs at 1.0GHz. That's because of a newer architecture and more cores.