Guys,
Respectfully, this thread contains several misconceptions. Let's get this straightend out and into perspective.
hasteveha,
Have you read the following Guide? Intel Core i7-920 Overclocking Guide -
http://www.xbitlabs.com/articles/cpu/display/core-i7-920-overclocking.html
Overclocking requires that processor and bus stability thresholds be established prior to finding memory stability thresholds, for which there are tested and proven methods. Temperatures are about understanding Intel's voltage and thermal specification, and not exceeding them.
Core i7 specifications:
Vcore Max = 1.375
Tcase Max (CPU temperature) = 68c
Tjunction (Core temperature) = 73c
Regarding Hyperthreading; when enabled, it can increase temperatures by as much as a whopping 33%. It's advantageous only for extrteme processor intensive games such as Flight Simulator X, or for audio / video encoding applications: Real World Gameplay CPU Scaling - http://enthusiast.hardocp.com/article.html?art=MTY0NCwxLCxoZW50aHVzaWFzdA==
Regarding processor longevity; excessive Vcore and temperatures will adversely affect overclock ceiling and CPU longevity over time, which is a process sometimes referred to as "Electromigration". Intel's term is "Processor Degradation" which is explained in the following article: The Truth About Processor Degradation -
http://anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3251&p=6
Regarding Line-Load Calibration; for your Asus P6T Deluxe V2 it should be enabled. Some of the more recent motherboards have improved designs for Vdroop compensation over older models. Formerly, Vcore would decrease sharply by as much or more than 64 millivolts from idle thru load, which required a higher Vcore setting in BIOS to provide stability at load.
The latest developments in Vdroop compensation allows a lower Vcore to be set in BIOS, which either remains constant from idle thru load, or increases by a minimum increment of 8 millivolts. The result is tighter voltage regulation and lower Vcore at idle and moderate loads, which in turn produces lower temperatures: Intel Processor Power Delivery Design Guidelines and Specifications: Vdroop Explained -
http://www.thetechrepository.com/showthread.php?t=126
Regarding overclocking and temperatures, there are many variables involved, so let's outline the basics.
Core i7's have a single CPU temperature sensor (Tcase), and four Core temperature sensors (Tjunction). For all Core i7's, Intel's Thermal Specification is 68c, which is shown in their Processor Spec Finder -
http://processorfinder.intel.com/details.aspx?sSpec=SLBCH
68c is maximum CPU temperature (Tcase Max), NOT Core temperature, which is a common misconception among many users. Also, there's a 5c Gradient between CPU temperature (lower) and Core temperature (higher), which is shown in the following Intel document -
http://arxiv.org/ftp/arxiv/papers/0709/0709.1861.pdf
Although maximum Core temperature (Tjunction Max) is 100c, which is for Throttle and Shutdown protection, the corresponding CPU temperature would be 95c; far too hot for sane operation. As such, CPU temperatures above 68c and Core temperatures above 73c should be considered as an "overtemp" condition.
SpeedFan shows CPU temperature AND Core temperature, while Real Temp shows Core temperatures ONLY. Both programs allow calibrations. Intel has stated that the Digital Thermal Sensors (DTS) used for monitoring Core temperatures are accurate at very high temperatures, become less accurate as temperatures decrease, and may be unreliable at idle temperatures.
On the other hand, the Analog Thermal Diode used for monitoring CPU temperature is linear from idle thru high temperatures, which is why, as per agreement with Intel, motherboard manufacturers do not include Core temperature in their monitoring utilities found on the installation disk, such as Asus Probe.
Never assume that default temperatures are accurate. The accuracy of CPU temperature is determined by BIOS calibrations, but can be closely calibrated in SpeedFan. The accuracy of Core temperatures are determined by Intel factory calibrations, but can be closely calibrated in SpeedFan and Real Temp.
Prime95 Blend, or OCCT (Linpack), or CPU Burn Test (LinX) are cyclic workloads that produce fluctuating temperatures, some of which are extremely high at 115% workload. While these are useful for stability testing, they're inappropriate for thermal testing. Prime95 Small FFT's is the standard for thermal testing, because it's a steady-state 100% workload. Since thermal saturation is reached within 7 to 8 minutes, a 10 minute test is adequate. Keep in mind that ambient temperature plays an important role, and even the most processor intensive games or applications will rarely exceed 70% to 85% sustained workload.
From the
Core i7 and Core 2 Temperature Guide:
http://www.tomshardware.com/forum/221745-29-sticky-core-core-temperature-guide
Scale 4: Quad
Ci7 9xx:
Tcase Max
68c, Stepping
C0, TDP 130W, Idle
16W
<--Core i7
QX6x50:
Tcase Max
65c, Stepping
G0, TDP 130W, Idle
16W
QX6800:
Tcase Max
65c, Stepping
G0, TDP 130W, Idle
16W
QX6700:
Tcase Max
65c, Stepping
B3, TDP 130W, Idle
24W
QX9650:
Tcase Max
64c, Stepping
C1, TDP 130W, Idle
16W
QX9650:
Tcase Max
64c, Stepping
C0, TDP 130W, Idle
16W
QX9775:
Tcase Max
63c, Stepping
C0, TDP 150W, Idle
16W
-Tcase/Tjunction-
--65--/--70--70--70--70-- Hot
--60--/--65--65--65--65-- Warm
--55--/--60--60--60--60--Safe <--
--25--/--30--30--30--30-- Cool
Any care to comment?
Comp
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