what temp monitor to use?

hey! i just put my 1.2 gig t-bird in with a Taisol hsf on a a7v mobo
straight away the bios said it was at 42c
Asus Probe told me that it was at 55c

i just changed it to 9 X 133 and now bios says its at 44c, where as Asus Probe says 56c

which one do i believe??
i'v heard some people say that Asus Probe isnt a very accurate program, so what one should i get?

thanx

asus probe, as people said, reads the temp 10 degree higher than reallity. I never Use Asus, just heard about its temp problem... too