which x2 3800 to keep? UPBW or XPMW

[xomp]

wondering if these will matter for OC'ing.

i have 3 cpu's right now
they're ADA3800DAA5BV
one of them is LDBHE 0542 UPBW
and the other 2 are 0540 XPMW

is there a different between these, or is it just a guess as to which one will OC better?

 

[Thor86]

OCing is all luck of the draw.