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Very low idle temp but very high load temp???

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  • Overclocking
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March 29, 2007 9:27:35 AM

I recently got my new E6600 and have been dabbling with overclocking. I have read all the stickies (of numerous forums, not just this one) but I'm not quite sure what the root of my problems are (my system specs are in my sig if needed).

At the moment I have the important settings as the following:

Multiplier: 9
Clock Frequency: 360
Vcore: 1.4000 (This is what its set at, it drops to slightly under 1.34 at 100% load according to SpeedFan)

The other voltages are set at the lowest choosable point (i.e. not auto). I used Core Temp, SpeedFan and TAT for my temp readings and all three are normally within 2-3 degrees of each other.

I am getting temperatures of around 23c -25c at idle (this is completely idle, as in after i have left the computer alone doing nothing for an hour or two) which seems pretty low. If I am just browsing the net, like right now, the temps are around 25c-29c. But if I run TAT for 10 min or so the temperatures jump up to around 59c which is a bit too hot for me to be comfortable with. Also this seems like a pretty massive jump when the normal idle-load delta is apparently under 20c and mine is 30c - 35c. I have reseated the heat sink a couple of times but that didn't seem to improve anything much more than possibly a degree or two. I am using the TIM which came with the Ultra 120 so maybe its not the best stuff in the world but its not going to be causing the problem on its own.

The ambient temp is pretty low, I'd be guessing 15c - 18c and my case has pretty decent cooling.

So what I'm asking is whether the large idle-load delta indicates what the problem might be to any of you experts? I'm perfectly happy with the speed of the processor as it is but I'd really like to know what is limiting me pushing it any further (I like to tinker). Windows tends to lock up after running TAT for 10+ min if I up the freq to 368MHz, and it wont even get to Windows at 384MHz and I have tried increasing the voltages a bit. How far should i push the voltages?

One thing to note perhaps is that the case configuration is reverse ATX (upside down) so the heatpipes on the motherboard may not be working correctly. But the "system" temp indicator in SpeedFan is always around 31c - 32c so if that's any indicator of the chipset temp it seems fine.

Any help would be greatly appreciated.

(I can't see my signature, maybe you can't see your own signature but I'll write my system specs here just in case it didn't post for some reason)
E6600@3240 (9x360) | Thermalright Ultra 120 w/ Vantec 120mm SF12025L Fan | 2GB Corsair PC6400C4D | P5B Deluxe WiFi | 8800GTX@600/1800 | X-Fi XtremeMusic | 2x320GB 7200.10 | Pioneer DVR-212BK | Corsair CMPSU-620HX | Lian Li PC-V2000 Plus II

More about : low idle temp high load temp

March 29, 2007 10:19:57 AM

Hmm well I just managed to drop the temperatures at load by 5-6 degrees by turning around one of my fans. It turns out I had the rear case fan blowing into the case (It was this way by default and I forgot about it). As the rear fan is directly adjacent to the CPU heatsink which had a fan on the other side of it trying to blow air through the heatsink and out of the case, this didn't work too well :oops:  .

The temps are still 53-54 at load. Should I be trying to go any higher with these temps the way they are? And do you raise voltages to combat instability? Which are the important voltages to raise (all of them?).

Thanks for replies.

EDIT:

After a bit more testing the load temps are:

- 54c with TAT (according to both Core Temp and SpeedFan, TAT says 52c - 53c)
- 44c with ORTHOS (according to Core Temp and SpeedFan, TAT says 42c - 43c)

The 44c temp seems nice and low so I think I'll push it a bit more. My idle-load delta is still over 30c though as my idle temp is down around 21-22 degrees now so I'd still like to know why the difference is so great. Could it really be all down to the thermal interface material? I could buy some AS5 if its going to make a significant difference.

EDIT 2:

I got up to 3.6 GHz (400x9) but it was completely unstable. I couldn't even run 3 seconds of ORTHOS before it failed with an error and TAT just caused the system to reboot after a few seconds. It was pretty stable up to 384 - 388 MHz FSB but I had to have a pretty high Vcore (1.5000 +). I think that the cooling on the northbridge is what's stopping me from going further as that seems to have been other people's problem and my upside down ATX case probably just makes it worse.

Still any other suggestions would be welcomed.
March 29, 2007 6:17:29 PM

Well, firstly I would have to agree with you that your load temps seem rather high.

I'm not sure using AS5 will give you the results you want. Check this link - an excellent review of Thermal Interface Materials that may lead you to question the reputation of AS5.

I have heard some rumours regarding convex/concave heatspreaders on some Conroe processors - this could be a potential cause of your problem.
March 29, 2007 7:18:59 PM

Try manually setting your memory timings in the bios to 5,5,5, 15. Also, you might want to adjust the memory frequency to a 1:1 ratio. I would try 3 ghz (333X9) and set your memory to 667 and do a stability test with Orthos and Memtest. You can set the vcore to 1.4 and gradually go down or until your rig is stable. I have a 6600 at 3 ghz, my idle is high 20's to low 30's however under full load with Orthos it gets to the 60's with stock hs and fan. But I never use my comp at full load usually I just play games on my Dell 3007 and my 8800GTX at 2560X1600. It never goes above 50 C.

Hope this helps :o 
March 29, 2007 9:24:28 PM

Quote:
Well, firstly I would have to agree with you that your load temps seem rather high.

I'm not sure using AS5 will give you the results you want. Check this link - an excellent review of Thermal Interface Materials that may lead you to question the reputation of AS5.

I have heard some rumours regarding convex/concave heatspreaders on some Conroe processors - this could be a potential cause of your problem.


If the heatspreader or the heatsink is not flat wouldn't this affect the idle temp as well? And I think my idle temps are pretty good. And I know AS5 isn't perhaps as good as its claimed but I live in New Zealand and I can't get Shin-Etsu x23 from anywhere. Maybe i can find Arctic Silver Ceramique though, I'll have a look around.
a b à CPUs
a b K Overclocking
March 31, 2007 10:46:28 PM

Please filter your info into the following format substituting your values for these:

Quote:
Results

Tcase (Motherboard Utilities) = 30c Idle, 50c Load (SpeedFan: CPU or Temp X)
Tjunction (TAT) Hottest Core = 45c Idle, 65c Load (SpeedFan: Core 0 / Core 1)

Variables

Ambient = 22c
Chipset = 975X
C2D = E6600
CPU Cooler= AC Freezer 7 Pro
Frequency = 3.6 Ghz
Load = TAT @ 100% 10 minutes
Motherboard = Asus P5W DH
Vcore = 1.45


Thanks,

Comp 8)
March 31, 2007 11:13:41 PM

Results

Tcase (Motherboard Utilities) = 33c Idle, 54c Load (SpeedFan: CPU or Temp X)
Tjunction (TAT) Hottest Core = 30c Idle, 56c Load (SpeedFan: Core 0 / Core 1)

Variables

Ambient = 25c
Chipset = 965
C2D = E6600
CPU Cooler= Thermalright Ultra w/ Vantec 120mm Stealth Fan
Frequency = 3.0 Ghz
Load = TAT @ 100% 10 minutes
Motherboard = Asus P5B Deluxe
Vcore = 1.375 (set in bios, not actual)

This is an abnormally hot ambient temperature though because today is really hot. Normally it would be around 15c - 18c. and the idle temps would be 5c+ lower.

(Edited to correct heatsink maker)
April 1, 2007 12:04:50 AM

Quote:
Thermaltake Ultra w/ Vantec 120mm Stealth Fan


Do you mean Thermalright ?

I would make sure that the heatsink is sitting flat on the heatspreader. With a massive cooler like that one, a considerable amount of force is required to make the cooler seat correctly.
April 1, 2007 12:26:11 AM

Quote:
Thermaltake Ultra w/ Vantec 120mm Stealth Fan


Do you mean Thermalright ?

I would make sure that the heatsink is sitting flat on the heatspreader. With a massive cooler like that one, a considerable amount of force is required to make the cooler seat correctly.

Yeah my bad, Thermalright it is. The screws which hold the heatsink to the motherboard are as tight as they can go and it hadly moves if I twist it so I think its seated correctly.
April 1, 2007 6:34:42 AM

Make sure that your heat spreader isn't concave, as I have heard of some people getting defective ones. If it is, the only way to fix it is to lap the heat spreader (or remove it altogether!) which means any warranty you did have is out the door, but thats the price you pay for overclocking!
April 1, 2007 6:46:57 AM

Quote:
Make sure that your heat spreader isn't concave, as I have heard of some people getting defective ones. If it is, the only way to fix it is to lap the heat spreader (or remove it altogether!) which means any warranty you did have is out the door, but thats the price you pay for overclocking!


Yeah that does seem to be one of the few remaining possible causes for my high temps so I'll have a look at that. Thanks
a b à CPUs
a b K Overclocking
April 1, 2007 6:54:46 PM

Sczee, as has been suggested, it's possible that your E6600's Integrated Heat Spreader may be slightly concave, which would account for your extended Tjunction Delta of 26, just on the edge of the 25 spec. Your temps are still comparatively cool, (just visualize the colored temp scale in the Guide), so feel free to target a higher OC. The only adjustment needed is Tcase, which is offset +10c. Use the "Offsets" section of the Guide to configure this correction.

Hope this helps,

Comp 8)
April 1, 2007 8:41:52 PM

Quote:
Sczee, as has been suggested, it's possible that your E6600's Integrated Heat Spreader may be slightly concave, which would account for your extended Tjunction Delta of 26, just on the edge of the 25 spec. Your temps are still comparatively cool, (just visualize the colored temp scale in the Guide), so feel free to target a higher OC. The only adjustment needed is Tcase, which is offset +10c. Use the "Offsets" section of the Guide to configure this correction.

Hope this helps,

Comp 8)


Thanks. So do you think that my Tcase readings (core 0 and core 1 in speedfan?) are ~10c higher than they should should be? How can you be sure that it is not the Tjunction reading which is ~10c too low? As I understand it they should be 15c apart but I can see no way of telling which one is incorrect.
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a b K Overclocking
April 1, 2007 8:48:38 PM

Please re-read the Guide:

Quote:
Thermal Flow

Heat originates within the Cores, and is hottest where the dual Tjunction sensors are located. Heat is then dissipated throughout the CPU die to the socket and motherboard, and to the Integrated Heat Spreader, where the single Tcase sensor is located between the Cores, and the temperature is ~ 15c cooler. Heat is then transferred to the CPU cooler, and finally to air inside the computer case. All 3 C2D temperatures are then determined by computer case cooling efficiency and Ambient temperature. Regardless of Load, Tjunction is always ~ 15c higher than Tcase, and Tcase is always higher than Ambient.



Hope this helps,

Comp 8)
April 1, 2007 8:58:16 PM

Quote:
This should make it clear:

Thermal Flow

Heat originates within the Cores, and is hottest where the dual Tjunction sensors are located. Heat is then dissipated throughout the CPU die to the socket and motherboard, and to the Integrated Heat Spreader, where the single Tcase sensor is located between the Cores, and the temperature is ~ 15c cooler. Heat is then transferred to the CPU cooler, and finally to air inside the computer case. All 3 C2D temperatures are then determined by computer case cooling efficiency and Ambient temperature. Regardless of Load, Tjunction is always ~ 15c higher than Tcase, and Tcase is always higher than Ambient.



Hope this helps,

Comp 8)

Yep I was just reading that. So the CPU temp (Tcase) in speedfan should be 15c lower than the core 0 and core 1 temps (Tjunction temps). But the CPU temp should also always be above ambient temp. My readings at the moment have CPU (Tcase) at 34c and the two core temps (Tjunction) at 30c and 31c. As I understand your guide, the two core temps should be ~15c above the CPU temp. For this to happen I would have to offset either the CPU temp -18c or the core temps +18c. The first option would give me CPU temps below ambient and the second would give me idle temps of ~48c. The first of these is impossible and the second though possible seems a bit on the high side?. Or have I got it all wrong? What do you suggest in any case?

Thanks

Just for additional information I am running at 3240MHz at the moment with the following temps as they were displayed in speedfan:

Idle:

CPU = 34c
Core 0 = 30c
Core 1 = 31c


8 hours of dual instances of ORTHOS:

CPU = 56c
Core 0 = 53c
Core 1 = 53c

10 minutes of TAT:

CPU = 57c
Core 0 = 58c
Core 1 = 59c

for some reason the normal delta of 3c between the CPU and Core readings disappears for this test.

Adjusting the temps for +18c to the Tjunction temps would give:

Idle:

CPU = 34c
Core 0 = 48c
Core 1 = 49c


8 hours of dual instances of ORTHOS:

CPU = 56c
Core 0 = 71c
Core 1 = 71c

10 minutes of TAT:

CPU = 57c
Core 0 = 76c
Core 1 = 77c

Which is over hot according to your guide.
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a b K Overclocking
April 1, 2007 9:40:18 PM

What Ambient and Vcore apply to these temps?
April 1, 2007 9:55:55 PM

Quote:
What Ambient and Vcore apply to these temps?


Ambient I am working out now ( I have a thermometer on my watch but obviously you have to take it off to get an accurate temp and it takes a good 15 min to drop to room temp) but I'd estimate between 17c - 20c.

Vcore is set in BIOS at 1.425 but drops to 1.368 under load (and to 1.392 at other times).

My heat score is 13 (or 12 depending on what a heavy overclock is) if you want to know that.
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a b K Overclocking
April 1, 2007 10:47:26 PM

Update Variables and Results (uncorrected):

Ambient = 20c
Chipset = 965
C2D = E6600
CPU Cooler= Thermalright Ultra w/ Vantec 120mm Stealth Fan
Frequency = 3.24 Ghz
Load = TAT @ 100% 10 minutes
Motherboard = Asus P5B Deluxe
Vcore = 1.425

Idle:
CPU = 34c
Core 0 = 30c
Core 1 = 31c

TAT:
CPU = 57c
Core 0 = 58c
Core 1 = 59c

Corrected Temps:

CPU = 24c
Core 0 = 30c
Core 1 = 31c

TAT:
CPU = 47c
Core 0 = 58c
Core 1 = 59c

Let's go with my original analysis for the CPU temp (Tcase) offset by +10c. Although in this instance, Tcase + ~15c = Tjunction is slightly converged under Load at ~12c, as you increase Vcore and OC, you'll see this difference diverge closer to ~15c. If ambient is correct, then Tcase Idle is resonable for your cooler and Vcore. Since TAT and SpeedFan agree, and the accuracy of the ~15c difference is more critical at Load, Tcase Idle is of less concern. Considering that sensor accuracy is +/-1c, and BIOS tables may not be precisely linear, it's OK if Tcase is a bit skewed at Idle. I believe that your Tjunction temps are accurate, and since temp inaccuracies are typically in 5c increments, it makes the best sense to configure a -10c correction in SpeedFan.

Hope this helps,

Comp 8)
April 1, 2007 11:00:36 PM

Thanks a lot I understand your reasoning but one problem is that now Tcase is reading 29c and the air coming out of the rear case vent (which is adjacent to the CPU heatsink) is about 21c - 22c. So if I lower the Tcase temp by 10c, it will be below the temperature of the air coming off the heatsink and I can't see how that would be possible.

Also one other thing to consider is that when I was stability testing at 3.24GHz with Vcore set at 1.375 the Tjunction temps were only showing 53c but after 10 minutes or so the computer rebooted. Is this only because the voltages were set too low or could this indicate that it was an overheating problem and the Tjunction temps are inaccurate? The fact that the system is stable at 3.24GHz now that I increased the voltages seems to suggest that it was only a voltage problem but its something to consider.

Thanks again for your input.

EDIT:

Ok something's definitely wrong now. I measured the temp of the air coming out of the rear vent more accurately and its 25.4c. And at the moment my Tcase temp is 27c and my Tjuncation temps are 23c and 27c. So the temperature of one of my cores is below that of the air coming off the heatsink 8O . That's some cooling...

Perhaps adding a +10c offset to the Tjunction temps would make more sense now?
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a b K Overclocking
April 1, 2007 11:25:33 PM

You may have misunderstood Ambient. It's defined in a very strict and lengthy Intel spec, but room temp generally works, which is quick and easy for most users to acquire by simply looking at the wall thermostat. A more accurate measurement is a thermometer near the computer's front air intake intake, which is usually floor level, where it's a few degrees cooler. Exhaust temp is of no consequence, except to note that the temp doesn't seem too warm. So let's go back one step and re-verify Ambient.

As for your stability, Vcore is indeed the most critical factor.

Comp 8)
April 1, 2007 11:44:37 PM

Quote:
You may have misunderstood Ambient. It's defined in a very strict and lengthy Intel spec, but room temp generally works, which is quick and easy for most users to acquire by simply looking at the wall thermostat. A more accurate measurement is a thermometer near the computer's front air intake intake, which is usually floor level, where it's a few degrees cooler. Exhaust temp is of no consequence, except to note that the temp doesn't seem too warm. So let's go back one step and re-verify Ambient.

As for your stability, Vcore is indeed the most critical factor.

Comp 8)


Ok well I'm not going to say Intel is wrong but I can't see how the air which is being blown out of the heatsink could possibly be hotter than the cores of the CPU which is providing the heat which the heatsink is dissipating unless there are other components providing a lot of heat to the intake of the heatsink fan which there aren't as far as I can see. But anyway the intake temp.

Unfortunately we don't have central heating (not many people do in New Zealand) so I don't have a wall thermostat. I've put the only two thermometers I could find (and they are both of doubtful quality) by the front intake vent of my case so I'll wait 10 min or so for them to stabilize and then get back to you.

As for my voltages some users of E6600s seem to be able to get to 3.4GHz plus with Vcores of as little as 1.3625 where as I have to have at least 1.4125v for stability at 3.24GHz. Is this purely because of variation between processors or could this be because of cooling?
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a b K Overclocking
April 1, 2007 11:58:31 PM

There are no CPU's 100% identical. C2D's have nearly 300,000,000 transistors, and every silicon nano-circuit is unique. Each has slightly different basic properties of electronics such as resistance, capacitance, inductance, impedance, and transconductance. Although two consecutive serial number CPU's from the same batch fabrication, with the same stepping codes, may appear identical, they're yielded from different location on the silicon wafer from which they're manufactured, and like diamonds, each has it's own unique flaws.

Even though their dynamic operational characteristics may be very similar, no two CPU's will overclock to exactly the same stable maximum speed, at the same Vcore, at the same temperature. Additionally, in a dual core processor, one core will always become unstable before the other. Sometimes you get a clean one, sometimes you don't. That's just the luck of the overclocking draw. How's that Ambient temp measurement going?

Comp 8)
April 2, 2007 12:09:32 AM

Yep cool that's what i thought.

Tha ambient temp seems to have stabilized at 19.2c which gives me final temp readings of:

Ambient = 19.2c
Chipset = 965
C2D = E6600 (revision B2)
CPU Cooler= Thermalright Ultra w/ Vantec 120mm Stealth Fan
Frequency = 3.24 Ghz
Load = TAT @ 100% 10 minutes
Motherboard = Asus P5B Deluxe
Memory = Corsair PC-6400C4D running at 1:1 (720MHz at 4-4-4-12)
Vcore = 1.425 (at load drops to 1.360)

Idle:
CPU = 27c
Core 0 = 23c
Core 1 = 25c

TAT:
CPU = 55c
Core 0 = 57c
Core 1 = 57c
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a b K Overclocking
April 2, 2007 12:52:39 AM

Now that we have the right info, this changes everything. Under the circumstances, according to your measurements, the only offsets which make sense is to split the difference, and configure SpeedFan to decrease the CPU by 5c, and increasae the Cores by 5c. Your Idle to Load Delta is clearly outside spec, so as has been previously mentioned, check your CPU for flatness.

Comp 8)
April 2, 2007 1:07:58 AM

Quote:
Now that we have the right info, this changes everything. Under the circumstances, according to your measurements, the only offsets which make sense is to split the difference, and configure SpeedFan to decrease the CPU by 5c, and increasae the Cores by 5c. Your Idle to Load Delta is clearly outside spec, so as has been previously mentioned, check your CPU for flatness.

Comp 8)


Thanks a lot I've got the offsets configured and the temps look a lot more sensible. Although the idle load delta is outside spec the temperatures themselves are easily within normal, with max temp of around 62 (Tjunction) with TAT. So although I might have a look at the concavity of the heatsink/spreader I think I'm safe to push the overclock a bit with the current setup.

Again, thanks a lot for all your help.
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a b K Overclocking
April 2, 2007 1:22:33 AM

You're very welcome, and I'm glad you agree. As much experience as I have looking at various temps, I'm not impressed with the manner in which Asus's tables are behaving on your board. You might try flashing the BIOS to see if the temps scale more typically, but as your temps are, this is the best compromise that I can justify.

If you're comfortable with this, then enjoy your rig!

Comp 8)
April 2, 2007 1:28:38 AM

Quote:
You're very welcome, and I'm glad you agree. As much experience as I have looking at various temps, I'm not impressed with the manner in which Asus's tables are behaving on your board. You might try flashing the BIOS to see if the temps scale more typically, but as your temps are, this is the best compromise that I can justify.

If you're comfortable with this, then enjoy your rig!

Comp 8)


The BIOS is at the latest version (1004) so unless an earlier version would give better readings I can't get any better there. I increased the overclock to 3384 (376 x 9) and the Tcase Tjunction delta seems to be 10c. If I increase the Tjunction offset by another 5c then the 15c delta is pretty much perfect under load so I think I'll do that. Thanks again.
!