how is voltage related to CPU temp?

[X14]

I just bought a new P4 2.4 ghz 533 FSB CPU. This CPU runs at 1.5v or so but it runs no cooler than my AMD 1600XP that was overclocked at 1503. The AMD CPU runs on 1.75v. Both CPUs operate at about 38C idle, and 44C full load. Both CPU are using the retail HSF units, the P4 is not overclocked at all. I was expecting somewhat cooler temps (32C - 38C) from the P4 being that it only runs on 1.5v. I've been out of the Intel loop for over 2 years so I'm not real familiar w/ the characteristics of Intel CPUs since the Celeron 300A days.

 

[Goi]

All other things being equal, a high voltage would mean a higher temperature, since Power = Voltage x Current(P=VI). The more power you produce, the hotter it would be, unless you're runnign at 100% efficiency which is impossible. However, since you're comparing 2 different CPUs with 2 different architectures, a lower voltage on one doesn't mean it would run cooler than the other. Other factors come into play as well, such as die size, cooling methods, load, what the CPU is doing with that voltage, etc...

Intel CPUs used to be cooler than AMD ones clock for clock, but with the higher speed P4s(including yours), they're around the same now...at least at the same "performance ratings". Intel's hottest is now hotter than AMD's hottest as well.

 

[thomsbrain]

Goi's got it all right. My P4 really cooks, and overclocked, the heat output is pretty tremendous.

 

[X14]

Thanks guys. I thought maybe I was doing something wrong so I took off and put back on the HSF 3 times re-applying Arctic Silver and everytime I got the exact same temps so I was convinced it wasn't due to bad contact when I put on the HSF. If this is considered normal temps than I'm happy. Thanks again.