q6600 g0 temps

stressed with orthos
cooled by a ultra 120 extreme and scythe fan (reading temps with core temp 0.95.4)
(2925 mhz and 1.080 Vcore [says CPU-Z, but in bios it's higer 1.375 or something)
core #0 55
core #1 55
core #2 28
core #3 28

Windows XP pro

how come that the temps are that different (core0/1 and 2/3) (i know they aint stessed but still)

thanks in advance