Duron 700 & 650 : different temperature behavior

[Serville]

I have 2 Durons; one 700MHz (Week30: 1.5V) overclockable to 1GHz at 1.85 and one 650MHz (Week40: 1.6V) overclockable to 850MHz also at 1.85.
Using the same board, I see a completely different temperature behavior between the two.
My 700@1000 at 1.85 goes up to 48C at idle, and only increase 3C to 51C highest at fullload.
However my 650@850MHz at 1.85 is only at 35-37C at idle, and increase to 48-50C at fullload.
Both processors were tested using the same mobo Abit KT7 & same heatsink.
I don't understand why there is such a different temperature behavior between the 2 processors when overclocked.
It seems that ACPI Halt Instructions does not give any effect to my 700@1000Mhz during idle, but it surely cools down effectively my Duron 650@850Mhz. It takes only 20-30 seconds for the Duron 650@850 to drop its fulllod temperature from 48C to 37-38C. This fast temperature drop could be attributed to the use of 72CFM fan blowing to the heatsink. However, my Duron 700@1GHz does not show the same pattern of behavior. At 51C fullload, it doesn't change much at idle. The temperature could only drop to 48-49C after 5 minutes, even with 72CFM fan blowing.

I notice many Duron users also experience the same anomaly. Some people claim to have only 2-3C difference between fullload & idle, while others can have a 10-12C difference.

I'm just trying to understand what might be the cause of such a different behavior. I remember that AMD has changed the Duron's core somehow after Week31, where the Durons start using 1.6V instead of 1.5V. Could this be the reason why the 2 processors act differently ?
Why my Duron 700@1GHz does not seem to benefit much from the ACPI's cooling instructions?
Anybody care to share their ideas to me ?

 

[Mikewarrior2]

ah, more Thermistor Inaccuracies. Unfortunately, I don't think there is an explanation for why the two temps are off. Try using a software IDLE program to see if the 700 Duron to see if that drops the temp lower.

Lastly, see the link in my sig. Socket A temps are fishy, even on the same MB.



Mike

 

[Serville]

Thanks Mike. Your page is very informative. I have saved it in my hd as ref doc.
I don't know why my Duron 700@1000 does not get benefit from ACPI cooling. My friend who used A7V also have the same problem, where his new non-overclocked Duron 700 (recent week) also stays at 49C idle and 51C fullload. Some Durons just cools better with ACPI , while some other don't.

 

[DaddyG]

Did you tey both the cpus at standard clock speed as a test ?? Interesting info, I don't believe that thermistor inaccuracy is the cause of all the discrepancies that we see.

 

[Mikewarrior2]

A7V Bios 1004B and later(i think) have problems with ACPI implementation. The way around this is with a manual software CPU Idler.

It would seem weird that a different cpu speed(assuming teh cpu is the same week, they would technically be from the same batch of silicon) would react differently to ACPI. WEre the two tests done at roughly the same ambient/room temp?


Mike