R9 280x Gigabyte windforce rev.2 @ 2.1Mh/s - Very loud card, around 73C when mining DRK
R9 280x Asus DCUII @ 2.1Mh/s - Very quiet and cold card, around 65C while mining drk
Sensei, what settings you used for 2.3 Mh/s ? :) or what miner version, please send link....