Q9450 Temperature Question - Core Temps

I just swapped out a Zalman 9700 for the 9700NT (with the 4-pin PWM connector) and replaced using Antec Formula 5 with Arctic Silver 5. The good news is that both my package and core temps dropped a few degrees. Initially, right after booting into windows my core temps were in the low 40s (27C ambient temp). Now they are in the high 30s. My concern is that I may need to reapply the thermal compound again. Three of my cores are running mid to high 30s and one is running at 27/28C. Values are from RealTemp. Granted I've only turned my computer on twice since installing the different heat sink and TIM so this may change as the compound "cures" but just curious if I should clean it all off and try again? I read the AS5 instructions although i didn't trust that I'd know if the whole heat spreader would receive TIM so I spread it around with cling wrap on my finger.

Ok...I redid the TIM (Arctic Silver 5) and these are the results from Real Temp 2.60:

Idle:
Core 0 - 35C
Core 1 - 35C
Core 2 - 38C
Core 3 - 38C

When I ran a full Prime95 Test (Small FFTs) my peak temps were:

Core 0 - 55C
Core 1 - 50C
Core 2 - 53C
Core 3 - 53C

System (Motherboard) temp hit 48C (according to HWMonitor)
Ambient Temp is 81F (27C) according to my hallway thermostat, although it feels a little warmer in the room where my computer is.

I believe these look to be respectable number for an air-cooled system overclocked to 3.2GHz, correct?

My VID is 1.25V and right now it looks like my BIOS has my processor running at just under 1.3V (auto setting). My concern was the difference in core temps. I've tried twice now, being very careful to get an even coating of thermal grease but I still get the 3 degrees difference at idle between Cores 0/1 and 2/3. As you can see there's a 5 degree difference between Core 0 and 1 under load, with Core 1 being the lowest at both idle and load. I just wanted to make sure this was a normal variation and nothing to worry about.

It'll be difficult to even out the temps of each core. I've had a few of the quads and only one was almost even, it was off by 1 degree. I tried lapping my others but it didn't help. If you have a screw type heatsink mount, you could try varying the tightness at each corner--this helps a little bit.

Thanks for the advice. I did research and it agrees with what you all are saying. Based on the location of the cores (top and bottom) supposedly cores 0 and 1 are typically a few degrees cooler than 2 and 3. After much difficulty I now have a stable overclock at 3.4 GHz. BIOS voltage is 1.35V and actual voltage, after heavy Gigabyte Vdrop my actual voltage at idle is 1.30V. Vdroop under load drops it to 1.25V. My temps at idle remain the same and go up to around 57 max under load.