Alright so there's the card, I am really seeking answers from real experts or people who own this card, but if you know what you're talking about that's fine too. I would like to know the average fps I can get with diablo III without overclocking... I will not be doing any of that.
-sapphire radeon hd 6870 256 bit
-NZXT apollo black chassis case (i installed a front fan)
-Corsair vengeance 8Gb RAM
-ASUS Black Dvd Burner Drive
-OCZ ZS series 750W 80 Plus bronze High performance power supply
-ASROCK H77 Pro4/MVP LGA 1155 MOBO
-Intel core i3-2120 processor
-Western Digital Caviar blue 500GB 720 RPM Hard drive
Frame rate is highly dependent on the resolution you game at.
Having said that, there's nothing special about Diablo III. The i3-2120 matched with the HD 6870 will give you excellent frame rates up to 1920x1080 (1080p) using high settings.