What would cause such huge Temp differnce in Two Different Cores ?

[Mir96TA]

Cpu is running at Stock Speed. P45 is a ChipSet
Cooler is XIGMATEK HDT
I use the Artic 5 for thermal Compand
Case is a Med Tower with Front in and Exhaust out Fan (Plus P/S Fan)

Any idea ?

 

[Interitus]

Bad thermal paste spread (air pocket) or un-even HSF mounting?

-edit-

picture didn't show up for me till after i posted...

I'd clean off the TIM and mount again. My i7 920 has a pair of cores that are 4-5*C apart across 3 different coolers and multitudes of mounts, so I'd say that a re-mount and TIM application could very well be the issue.

 

[Mir96TA]

Hmm I need to get some new Thermal Grease
Artic 5 is all Gone
May be this time I might Get ARCTIC COOLING MX-2 let see how much better they are
So Far Artic 5 is been Good to me