Core i7/X58 Overclocking Thread

[fornowagain]

Personally I'd not want to run in the 90's for long, mine just bsod near a 100C on the stock cooler. But permanent damage if you stay under the TCC, throttling is not even active yet?

http://download.intel.com/design/pro...hts/320834.pdf

The Adaptive Thermal Monitor feature provides an enhanced method for controlling the
processor temperature when the processor silicon exceeds the Thermal Control Circuit
(TCC) activation temperature. Adaptive Thermal Monitor uses TCC activation to reduce
processor power via a combination of methods. The first method (Frequency/VID
control, similar to Thermal Monitor 2 (TM2) in previous generation processors) involves
the processor reducing its operating frequency (via the core ratio multiplier) and input
voltage (via the VID signals). This combination of lower frequency and VID results in a
reduction of the processor power consumption. The second method (clock modulation,
known as Thermal Monitor 1 (TM1) in previous generation processors) reduces power
consumption by modulating (starting and stopping) the internal processor core clocks.
The processor intelligently selects the appropriate TCC method to use on a dynamic
basis. BIOS is not required to select a specific method (as with previous-generation
processors supporting TM1 or TM2). The temperature at which Adaptive Thermal
Monitor activates the Thermal Control Circuit is factory calibrated and is not user
configurable. Snooping and interrupt processing are performed in the normal manner
while the TCC is active.

When the TCC activation temperature is reached, the processor will initiate TM2 in
attempt to reduce its temperature. If TM2 is unable to reduce the processor
temperature then TM1 will be also be activated. TM1 and TM2 will work together (clocks
will be modulated at the lowest frequency ratio) to reduce power dissipation and
temperature.

If TM1 and TM2 have both been active for greater than 20 ms and the processor
temperature has not dropped below the TCC activation point, then the Critical
Temperature Flag in the IA32_THERM_STATUS MSR will be set. This flag is an indicator
of a catastrophic thermal solution failure and that the processor cannot reduce its
temperature. Unless immediate action is taken to resolve the failure, the processor will
probably reach the Thermtrip temperature (see Section 6.2.3 Thermtrip Signal) within
a short time. To prevent possible permanent silicon damage, Intel recommends
removing power from the processor within ½ second of the Critical Temperature Flag
being set

Regardless of whether or not Adaptive Thermal Monitor is enabled, in the event of a
catastrophic cooling failure, the processor will automatically shut down when the silicon
has reached an elevated temperature (refer to the THERMTRIP# definition in
Table 5-1). THERMTRIP# activation is independent of processor activity. The
temperature at which THERMTRIP# asserts is not user configurable and is not software
visible.

TjMax can be read from each Core i7 processor but when Core Temp 0.99.3 was originally released, I don't know if Intel had released that information yet. If you want to double check you can try using RealTemp 2.83 which I know reads that new information. Don't copy the new .exe into your old directory or it will use your previous TjMax values from your INI file.

From early testing it seems that the Core i7 has more real world temperature head room available. The previous Core 2 Duo based Quads tended to lose Prime stability when well overclocked at about 70C. I've already seen screen shots of Core i7 running Prime stable at 80C and 90C like Pt1t is running in his screen shot above.

If your Core 2 Duo was running Prime stable, temperature was never an issue and it appears for Core i7, it is even less of an issue. By all means, the cooler the better but if Intel didn't think these could run reliably at 100C then they would lower the TjMax and start thermal throttling 10C or 20C sooner to prevent this.

My only concern from the screen shots so far is excessive voltage. We won't know how much is too much until more retail processors start getting used and the "my processor degraded" reports start coming in.

Edit: Thanks to coolaler for showing us what Core i7 thermal throttling looks like.



http://forum.coolaler.com/showpost.p...8&postcount=12

RealTemp will log any thermal throttling episodes and it looks like core0 at 98C and core1 at 100C both hit the throttle. You definitely want to keep it below this level or else your multi will start to cycle down to 12.0 which will kill performance. Core2 and core3 both hit 93C which is still OK. No throttling has occurred on these two cores.

Good news is that it didn't crash.