I'm build my first gaming pc, and I'm trying to decide between 2 different GPU's. They are the same price, and they are both 7870's. One of them has a core clock speed of 925 and a memory clock speed of 1500. The other has a core clock speed of 1000 and a memory clock speed of 1200. I'm not sure which would be better (as in higher fps). This is the rest of my build:
AMD Fx-8350 CPU
ASUS Sabertooth 990FX Motherboard
Kingston HyperX 3k 120gb SSD
Corsair Vengance 8gb (2x4gb) 1600
I guess it actually depends on what you are planning to do with the card. If it's for gaming on a single screen the core clock speed would be the most important. If you like to run high anti aliasing or more than one screen the memory clock could be an important factor.
The 7870 is a good card for overclocking (in most cases) so I think I would personally buy the card with the 925 core clock speed and overclock it to (hopefully) >1000 MHz. 1500 memory clock speed is actually pretty high for this card.
Do you have a link to the cards?