X800 XT and X800 XT PE, whats the difference?

[jagare]

I'm not sure which company is best for the X800XT, on some I see it labeled as an X800 XT PE and some just X800 XT, whats the difference between the two?
http://www.newegg.com/app/ViewProductDesc.asp?description=14-125-149&depa=1

Is that one any good? If not what company do you guys recommend?

[DanIdentity]

The regular XT has clocks of 500/1000 for core/memory. The XT PE has clocks of 520/1120.