Xtreme Low Q6600 G0 Temp on Air !!! (Lots of Pics)

[fornowagain]

...also note that 'Tjunction' is also (and perhaps more properly) known as 'maximum Tcase value'.

snip

I'd say that's close, but Tjunction and Tcasemax are not the same thing. Tcasemax is the maximum temperature for the IHS. Its on page 74, here, 62.2C for the B3 Q6600. The Tjunction is the on die temp, Tjmax is the maximum die temp. Tcontrol is the delta to the the thermal trip point TCC and has a negative direction -ve, as the the core heat increases the Tcontrol tends to zero. TCC is the throttling temperature. There is some debate, but Tjmax is not TCC. Tjunction is a generic value for a cpu type and the TCC value is the factory set value and can't be read externally, probably within a few degrees. So programmes like coretemp are accessing a register or assuming a value, if thats assigned correctly or reflects the actual Tjmax is a different matter.

Tcase for the Intel® Core™2 Quad processor Q6600 and Intel® Xeon® processors X3220 and X3210 on G-0 stepping has been increased by 11oC. Tcontrol offset will remain the same relative to increase in Tcase which will help reduce acoustics

That's saying the Tcasemax is now 73.2C (71C), the throttling point has the same offset as before so TCC has also increased by 11C. The short of it is that accurate absolute values are problematic, different programs use different values. Coretemp could well be reading the wrong register values for Tjmax and its not the 'actual' throttling point. Without an overheating throttling chip and a thermocouple attached, its still going to be guess at an absolute value.

Have a read on these links it might clarify a bit on the finer details. The first one is where I've tried to explain it as best I can; but you're right the deltaT via DTS is all that really matters. In techno speak its, "PROCHOT# is activated when DTS=0 for the maximum safe operating temperature."

http://forums.overclockers.co.uk/sho...8&postcount=14
http://www.xtremesystems.org/forums/...d.php?t=131008
http://www.xtremesystems.org/forums/...d.php?t=136804

One point though, if you know the temperature of the air blowing over the HSF and you know the approximate thermal resistance of said HSF. Then for stock voltage and speeds then the chips wattage will be close to the curves specified by Intel specs. If you know that lot, then you "should" be able to calculate an approximate value for Tc. At least then you'll know how accurate the PECI bios temps are! There's a worked example in the link above if you can be bothered.

The only thing I'd add, which may or may not be obvious is...

- A G0 stepping Q6600 at xxxMHz @1.5v very likely runs the same temps as a B3 stepping Q6600 at the same xxxMHz @ the same 1.5v.

If the G0 has a lower vcore at default that the B3 and ends at the same vcore at a higher clock it could end up using MORE power even with a lower TDP. The additional power used comes from change in voltage squared. Obviously its not very likely as a lower default vcore generally means a lower vcore for the same clock.

1. Q6600 B3 @ 3.6GHz 1.275v stock, 1.50V oced.

Pd = 105*(3600/2400)*(1.5/1.275)² = 217W

Suppose for a G0 a lower stock vcore and TDP, frequencies the same, so its the change in voltage that counts. Its using more!!

2. Q6600 G0 @ 3.6GHz 1.20v stock, 1.5V oced.

Pd = 95*(3600/2400)*(1.5/1.20)² = 222W

Now if it uses less voltage, but the same overvoltage delta. Which is fair if its the same process.

3. Q6600 G0 @ 3.6GHz 1.20v stock, 1.425V oced.

Pd = 95*(3600/2400)*(1.425/1.20)² = 200W