i know this things been asked for many times...
but i still curious because review of 3rd party heatsink always said that i7 cpu on idle stay around 30C and on load it goes around 68C
running prime95 for an hour indeed give me 68C
but what make me curious is my idle temp that stay around 40-45C,
well it more to light use, like firefox running on background (standby) and those windows sidebar (cpu.network usage monitor etc)
do you guys think my system temp ok under light usage (cpu usage <15%) ?
I'm still using the stock fan for my i7 950, and my idle temps are 30-35C. I don't know what kind of software you may have running in the background, but a 40-45C idle temp is a bit high. If you can run Prime95 for an hour and have the temperatures hover around 68C, you're golden (mine rises to an embarrassing 85C after a few minutes, but the fan is stock).
It depends a lot on the environment temperature. I live in Brazil and, right now, it's around 28C, so 30C is impossible to get.
About your light use, 15% sounds high.
I use Core Temp and it shows something like 1% or 2% in 1 or 2 cores when it's idle.
Maybe you just have to many stuff running background.