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skottish

Forum Fellow

From: Here

Registered: 2006-06-16

Posts: 7,942

AMD X2 6400+ and lm_sensors

I just swapped out my AMD X2 5200+ for a 6400+, and the first thing I thought was that this thing runs very hot. I know that is to be expected to some extent, but it seems a lot hotter than it should be. All I'm doing is typing this in Firefox, and these are the readings:

it8716-isa-0290
Adapter: ISA adapter
VCore:       +1.41 V  (min =  +0.00 V, max =  +4.08 V)
VDDR:        +1.86 V  (min =  +0.00 V, max =  +4.08 V)
+3.3V:       +3.41 V  (min =  +0.00 V, max =  +4.08 V)
+5V:         +5.05 V  (min =  +0.00 V, max =  +6.85 V)
+12V:       +12.03 V  (min =  +0.00 V, max = +16.32 V)
in5:         +3.28 V  (min =  +0.00 V, max =  +4.08 V)
in6:         +1.12 V  (min =  +0.00 V, max =  +4.08 V)
5VSB:        +5.00 V  (min =  +0.00 V, max =  +6.85 V)
VBat:        +3.15 V
fan1:       1247 RPM  (min =    0 RPM)
fan2:       1544 RPM  (min =    0 RPM)
temp1:       +28.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = transistor
temp2:       +40.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = transistor
temp3:       +25.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = thermal diode
cpu0_vid:   +1.550 V

k8temp-pci-00c3
Adapter: PCI adapter
Core0 Temp:  +34.0°C                                    
Core1 Temp:  +42.0°C

I've been reading that the maximum temperature for this chip is 63C. I can get to 61C on Core1 in less than a minute while encoding a video using two threads (Core0 is only maxing at 55C?). That's with total processing power only reaching around 84% (conky's figures). I have a very well ventilated case, and a good CPU fan with a deep, copper heat sink (set with Arctic Silver 5), two other large fans, and a CPU side vent. I use to be able to encode graphics at 100% processing power on both cores for over 20 hours with no problems. I'm not sure that this machine will last 10 minutes.

I know that the obvious answer is "go out and spend money on a better cooler". I'd like to understand a little more before I do. I don't have a lot of money, and I'd like to know if something is wrong here first.

So, here are my questions: At idle, why is Core1 reading eight to nine degrees hotter than Core0? What is the technical difference between the temperature readings above?

skottish

Forum Fellow

From: Here

Registered: 2006-06-16

Posts: 7,942

Re: AMD X2 6400+ and lm_sensors

After searching for days for an answer, I think I may have found it. The relevant temperatures are the temp1, 2, and 3, listings from the it8716* section. The core temperatures would work out to be:

first core = (temp1 + temp2)/2
second core = (temp2 + temp3)/2

where temp 1 and 3 are the temperatures on the die, and temp 2 is the overall CPU temp.

The k8 listing then has Core0 correct. I think it's failing on Core1 because it's confused between the difference of 2 cores and 2 processors. I'm not 100% sure, but I believe that it's currently averaging the CPU temp and either the motherboard temp, or the ambient case temp.

skottish

Forum Fellow

From: Here

Registered: 2006-06-16

Posts: 7,942

Re: AMD X2 6400+ and lm_sensors

It's important to mention that this is specific to at least my motherboard, a GA-M55PLUS-S3G from Gigabyte.

Fackamato

Member

Registered: 2006-03-31

Posts: 579

Re: AMD X2 6400+ and lm_sensors

Easy way to check that CPU temperatures are real: Put your finger on the heatsink, close to the CPU, and feel its temperature. If you burn your finger it's over 54c or so.