I7 920 temp variance and the effect of cpu multiplier?

I'm wondering what the effect of multipliers and BCLK on the temperatures of the 920 are. Situation:

I overclocked to 3.66ghz (183MHz x 20) with speedstep, turbo, HT enabled. I had vcore:1.275v, PLL:1.8v, QPI/DRAM:1.275v, and DRAM:1.6v, everything else on Auto. My ambient temperature is about 24°C. Please note I'm using SpeedFan to measure the following temperatures, and have an aftermarket HSF installed.. Idle - Cores: ~32°C, CPU: ~30°C , Load - Cores: ~67°C, CPU: ~60°C (recalling from memory, sorry)

I wasn't happy with the speed of my RAM, though, since it's spec'ed at 1600MHz but was running at around 1467MHz. Note I left all of the voltages the same, except DRAM bumped to 1.64v. I changed to roughly 3.67GHz (193MHz x 19), with HT enabled, and speedstep/turbo off. My RAM was boosted to 1547MHz. SpeedFan measures Idle - Cores: 20-23°C, CPU: 31°C, Load - Cores: 51°C, CPU: 59°C


So with what seems to be a practically equivalent overclock in terms of speed, and with the same voltages set (unless the other Auto settings have something to do with it..), why such a decrease in core temperatures of around 10°C? Both profiles were tested with P95 and proved stable so far. Also, my understanding was that the CPU Core temperatures, measured within the CPU, would always be higher than the CPU temperature as reported by the motherboard, but this isn't the case in the second configuration. I'm relatively new to overclocking and am trying to learn more, so does anyone have any insight? Thanks

Thanks, I didn't know that about SpeedFan. I tried RealTemp and am getting core temps more in line with my CPU temp. I think I might switch back to the first profile. Thanks again