AMD CPU Phenom II 955 Black Edition Quad Core Processor (Overclocking speeds)

Just wondering what sort of speeds people have got out of this processor, am thinking of overclocking mine.

Also what type of Cpu fan are people using?

Thanks.

Some have hit high 3.8-9, few hit 4 most will go 3.4.3-8 on air. get a frio with dual fans and watch your temps