How do you measure 'load' temps on i7

I'm running 3.8GHz (BCLK=190 x20, vCore 1.32) on the i7 920 on Asus P6T. No sign of failure after 6h of 8xORTHOS.

But I have a hard time figuring out if my temperatures are OK. I have probably read about different forum threads this w-e, very hard to get a definitive answer.

How do people typically measure 'load' temperature ? I see in 75% of the posts to use Prime95.

If I load 1 instance of Prime95, it only gets to anywhere between 53% and 67% cpu utilisation, with temps as follow:
(using lapped TRUE120 with 2x 44CFM fans in push-pull)


Mobo: 45c, CPU: 47c, CPU0: 58c, CPU1: 58c, CPU2: 56c, CPU3: 56c


That seems to be in line with what the majority is getting (30-40c idle, 50-60c load).

But if I load 8 instances of ORTHOS, the story is very different. Then I get truly 100% utilization (on all 8 cores, i.e. 4 cores w/ HT)
Then the temps go much much higher:


Mobo: 46c, CPU: 78c, CPU0: 88c, CPU1: 88c, CPU2: 85c, CPU3: 85c


This is measures with Everest, CoreTemp and RealTemp. They are all within 1c of each other.
SpeedTemp reports much lower temps (same load w 8xORTHOS):


Mobo: 46c, CPU: 78c, CPU0: 72c, CPU1: 69c, CPU2: 68c, CPU3: 60c


1. What does the majority consider 'load' : 1 x Prime95 (53-67%cpu), or 8 x ORTHOS (100%cpu) ?

2. Am I correct to trust Everest+CoreTemp+RealTemp since they yield [pretty much] the same numbers ?

3. The normal/nominal operating temp for i7 is 67.5c -- is that for the CPU, or for each core (CPU0,1,2,3) ?

4. Is it a bad thing to get 88c on a full 100% load ? Such load in real life is very unlikely, but is it bad ?

After talking to some local folks I realized I'm prolly using an obsolete version of Prime95, since it *should* exercise *all* cores at 100%.

I just got 2x Scythe SFLex 1600rpm for push/pull on the TRUE 120, will report new measurements tonight with up-to-date Prime95 load.

On because hyperthreading is a nice application to have because it can increase performance and multitasking by 15%, so unless you can get a 15% or greater overclock by disabling it, it is nice to keep it on. (It's also nice to have for folding@home or boinc apps)

After an evening well spent, I am pleased to report the satisfying results

The short version:
I lowered the temps by 22.5c !
- 7.0c with new fans push/pull & better thermal paste application
- 10.75c with HyperThreading OFF
- 3.4c with lower vCore

The long version:

0. Initial specs and cooling:
Stock i7 920 on P6T with default bios settings
Coolermaster Storm Sniper:
-Front: 200mm 1000 RPM 142 CFM
-Bottom: -
-Side: 200mm 1000 RPM 142 CFM
-Top: 200mm 1000 RPM 142 CFM
-Rear: 120mm 1200 RPM 30 CFM
TRUE 120:
-Push: oem 1600RPM 63.7CFM
-Pull: -

Temps Idle: Mobo=51 CPU=39 CPU0=43 CPU1=40 CPU2=44 CPU3=38


1. Add bottom fan + pull on TRUE120 : avg -3.6c idle
-Bottom: Scythe Slipstream 800RPM 40CFM
-Pull: Scythe Slipstream 800RPM 40CFM

Temps Idle: Mobo=47 CPU=39 CPU0=40 CPU1=40 CPU2=37 CPU3=37
Temps Load: Mobo=47 CPU=60 CPU0=58 CPU1=58 CPU2=56 CPU3=56


2. Overclock @ 3.80: avg +4.0c idle +29.5c load
-BCLK: 190
-vCore: 1.30
-DRAM: 1.65

Temps Idle: Mobo=46 CPU=35 CPU0=44 CPU1=44 CPU2=41 CPU3=41
Temps Load: Mobo=46 CPU=78 CPU0=88 CPU1=88 CPU2=85 CPU3=85


3. New fans + reapply thermal paste : avg -2.5c idle -7.0c load
-Rear: TRUE120 oem fan 1600RPM 63.7CFM
-Push: S-Flex 1600RPM 63.7CFM
-Pull: S-Flex 1600RPM 63.7CFM
->Could the TRUE120 actually be using the S-Flex 1600 as its oem fan ?
-Re-apply thermal paste with single pea-size dot instead of previous (oversized) + shape

Temps Idle: Mobo=48 CPU=36 CPU0=41 CPU1=41 CPU2=39 CPU3=39
Temps Load: Mobo=48 CPU=75 CPU0=82 CPU1=80 CPU2=78 CPU3=77


4. Turn off Hyper Threading: avg -0.5c idle -10.75c load

Temps Idle: Mobo=47 CPU=38 CPU0=41 CPU1=39 CPU2=42 CPU3=36
Temps Load: Mobo=47 CPU=65 CPU0=71 CPU1=69 CPU2=68 CPU3=65


5. Lower vCore from 1.30 to 1.275 : avg -1.25c idle -3.4c load

Temps Idle: Mobo=43 CPU=38 CPU0=40 CPU1=38 CPU2=40 CPU3=35
Temps Load: Mobo=45 CPU=64 CPU0=67 CPU1=64 CPU2=64 CPU3=61


Again, in brief:
- 7.0c with new fans push/pull & better thermal paste application
- 10.75c with HyperThreading OFF
- 3.4c with lower vCore
- 22.5c total

It's true that turning HT off significantly drops temps. However, depending on what kind of applications you'll be running, it might be better to drop your OC just a hair and leave HT on. If you'll be doing rendering, video encoding, or similar highly threaded, processor limited applications, you'd be best off leaving HT on.