PowerColor Radeon HD 7850 PCS+ Review @ OCC
 

Overclocking PowerColor's HD 7850 PCS+ is much like overclocking any of the 7XXX series of Southern Islands GCN core-based video cards as it relates strictly to overclocking. Each core and memory combination is going to to have its limits. First off using PowerColor's Powerup Tuner utility limited the clock speed on the core to a maximum of 1050MHz on the core and 1425MHz on the GDDR5 memory. Having seen speeds in excess of 1200MHz on just about every GCN card I have tested, I felt this was a bit low and moved to a different utility that allowed a higher core clock on the core. Sapphire's TriXX utility was able to deliver this added clock speed and allowed the clock speed on the core to scale well up and over the 1200MHz mark. A 235MHz boost in GPU speed is worth the added work to get there in this case. The Elpida-based memory was not as flexible when it came to overclocking with a maximum of 1400MHz stable. The memory clock speeds were not able to overclock high enough to really add a significant amount of memory bandwidth to help the benchmarking scores. Even so they still managed to improve by 175MHz.

http://www.overclockersclub.com/revi...n_hd_7850_pcs/