HT makes processor run cooler at idle?

[OddTSi]

Just put together a new system with a P4C and I've noticed that with HT on the CPU runs considerably cooler. As reported by ASUS Probe, with HT on my CPU/Mobo temps are 30/39, with HT off temps are 38/41. After 15 minutes of full load (the temps maxed out after the first 5 minutes of full load so I don't think running it any longer would make much difference) is 43/44 'off', and 44/45 'on', so not much of a difference there. But idle temps are what really shocked me.

Also, I've noticed that with HT on cpu voltage is slightly higher (1.568v 'off', 1.616 'on'). Have other people also noticed these voltage/temp differences? I tried switching HT on and off a few times to double and triple check the temps, each time letting it sit for a good while to make sure it reached idle temp, and the results were the same every time.

 

[Accord99]

Yeah, that seems to be everybody's experience with a HT processor.
XBitlabs did some measurements and noted the same thing.

temp graph
from this article:
http://www.xbitlabs.com/articles/cpu/display/p4-temp.html

 

[OddTSi]

Cool. Thanks for the quick reply. Nice to know it's a normal thing and not a malfunction somewhere.

 

[Duvie]

I don't run considerably cooler!!! I am running same overall speed and same vcore and on this Abit mobo I am running 3-4c hotter then my 2.4b at same speed and vcore...

 

[jiffylube1024]

Originally posted by: Duvie
I don't run considerably cooler!!! I am running same overall speed and same vcore and on this Abit mobo I am running 3-4c hotter then my 2.4b at same speed and vcore...

But what about on the same chip with HT on/off?

 

[OddTSi]

I was refering to the same processor with no changes (other than HT being on or off) made, like jiffylube1024 mentioned.