Which temps should I believe?

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Which temps should I believe?

Post by karmasalad » Wed Oct 31, 2007 5:08 am

I seem to get significantly different numbers between Core Temp 0.95 and SpeedFan 4.33.



Ambient temp is around 13C. Load temps are with 4 instances of Prime 95 running for about 5 hours. I'm using an Ultima-90 with Scythe SFF21E fan at stock speed.

It's odd that Core Temp's Tjunction rating never budges from 100C, regardless of load.

Should I be concerned about these temps? The Ultima got bumped and wiggled a couple of times while mounting it into my Solo case. I'm not looking to win top honors for cooling though. Just want it to be cool, quiet and stable.

Also, does anyone happen to know what Temp1 and Temp2 are representing in SpeedFan? My motherboard is the Gigabyte P35-DS3P Rev 2.0.

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Post by mexell » Wed Oct 31, 2007 6:46 am

You shouldn't worry at all. Both these temps are fine.

The difference is probably explained in the way the temperature is calculated: The CPU reports not an absolute value, but the remaining difference to the throttling temperature. The throttling temp of a CPU is afaik something specific to each CPU which is applied to it during final testing. I think (but I don't know for sure) that Tjunction is the temperature which the program assumes to be the throttling temperature.

By the way, have you tried TAT? It's made by Intel, maybe it's more precise.

And it's pretty cold at your place. Maybe you should start folding for SPCR to get a little warmer :D

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Post by Blue_Sky » Wed Oct 31, 2007 7:42 am

I'm a little wary of TAT, with both cores running at 100%, neither hit 35 degrees after a half hour. On the other hand CoreTemp shows between 12 and 16 degrees higher, which sounds much more reasonable. On idle, TAT shows exactly (a change in TAT is followed by CoreTemp about a second later) 15 degrees less than CoreTemp, which seems a little fishy to me.
Either way, your temps look fine.

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Post by karmasalad » Wed Oct 31, 2007 8:40 am

Thanks for the reassurances.

I probably underestimated my ambient temps. It's about 13C outside, so I guess it's prolly more like 20C or so inside. :)

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Post by nick705 » Wed Oct 31, 2007 12:57 pm

mexell wrote: By the way, have you tried TAT? It's made by Intel, maybe it's more precise.
IIRC TAT isn't altogether reliable for C2D/C2Qs, and also Speedfan is known to underread Quad temperatures by 15C (fixed in the latest beta version I believe).

The CoreTemp values look about right - a little better than mine with similar hardware and cooling, although my ambient temps are a bit higher...

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Post by Nick Geraedts » Wed Oct 31, 2007 2:54 pm

On my workstation (see sig), CoreTemp is the only program that gives me accurate temperatures. I've got my system overclocked to 3GHz and undervolted to 1.275V (BIOS setting), and I get a maximum load temperature of about 45C. This is with the TRU120E heatsink mind you - far better than with stock cooling.

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Post by quorton » Thu Nov 01, 2007 2:34 am

TAT was designed for notebooks, not really suitable for desktops.

There are 2 Q6600 out there, the B3 and G0 stepping. The B3 stepping has a max core temp of 85c, the G0 has a max of 100c.
The problem lies in how speedfan reads the temp, it doesn't read the actual temp, but reads the difference between the temp and max core temp. In other words, it reads how far the temp is from the max core temp.

But speedfan 4.33 doesn't know about the G0 stepping and uses the max coretemp of 85c.
Example: speedfan reads 40, so calculates temp as 85 - 40 = 45c, but for a G0 it should be 100 - 40 = 60c

Beta 4.34 solved this, you can get it by registering (2 second job)

You can check which stepping you have with cpu-z

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