the e5xxx chips seem to be hit or miss. Of the 2 I've dealt with, both e5300s, one maxes out @~3.9ghz, but runs 3.75ghz easily with only 1.3v. The other went straight to 4ghz with modest voltage, and maxed @~4.2ghz with ~1.4v. Getting them to run a decent FSB speed is just about impossibe. With the stock at 200mhz, anything over 300mhz is gravy. I was able to run up to 400hmz fsb, but with a severely lowered multi on both.
Still...for well under $100 it's a good chip. Great for a gaming only rig where more budget goes towards the gpu.