From one of the reviews I saw of a 1GB 7850 vs a 2GB, that extra GB doesn't offer much improvement until you're over 1080p. What games do you play? If none of them are brand spanking new, the 6870 should do just fine.
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on how to make your PC work for you. Referred by dark2099 please!
Mini Rig: Biostar TP67XE / i5 2500k / Corsair H55 / 2x4GB PNY / XFX 7770 / Corsair CX500M / Win 8 64 bit / Thermaltake V9 Blackwidow