to evertonfan, the 280x minimum core speed is 400mhz in that case of overheating, his still be mining at 350kh/s, not like a 4kh.

to newbie, set your target temp to 92, overheating to 94, shutdown temp to 95.  This will slow down your GPU fan a lot. The fan bearing will be the first part wearing out in few month if its runing 100% speed. And AMD said 94 degree is perfect for 280x cards and I find it so. Plus it will make your pc much quieter and you can be sure that cgminer will almost never slow you down for protection.