[SOLVED] Q9400 overheating issues

[Dadrian Daedalus]

I have an old lga 775 pc with a core 2 duo cpu running on a g41 mobo .

Today i replaced the older processor with a core 2 quad q9400 that i had lying around. Then i reinstalled the hsf after applying a small amount of themal paste.

The system now idles at around 44 C but upon load (such as while playing high bitrate 1080p videos at 50-60% cpu utilization), the temps go upto 68-73 c.

Is it ok to use this cpu like this?Is there any risk that the cpu or mobo may get damaged due to the high temps during load conditions? Acc to intel, the Tcase temp of this cpu is 71 C.

Previously when I had the c2d cpu, temps didn't exceed 65-67 C under load.


The cooler being used is a generic one btw.

 

[SamirD]

Sounds like your previous processor was a 65w one and the q9400 is a 95w one.

You have two options for safe operation. One is to replace with a cooler designed for a 95w+ tdp. The second is a technique that I have found to work almost in all cases, but will increase noise--set the cpu fan to 100%. If you cannot set the cpu fan manually to 100%, you can remove the blue pwm pin from the connector and that will force the fan to run at 100%. You may also have to set the case fan to 100%. But this should keep the cpu <55c in all cases.

 

[william p]

Often there are 2 different heatsinks available. The 65W 2 core usually has an aluminum finsink, and the 4 cores will have some type of copper. or heatpipe cooler for the 95W 4 cores.
If it's an ATX with the Intel cooler thaere is an aluminum one, and a copper core version.
https://i.ebayimg.com/images/i/132096950675-0-1/s-l1000.jpg
If it's Dell, or HP there may be proprietary parts.

 

[geofelt]

I think you are ok,

73c. is ok, the throttle point is around 100c.
What is your ambient temperature?
44c. seems a bit high for a normal 23c, ambient.

The pushpin system can be tricky to get right.
Look at the back of your motherboard to see that all 4 pushpins are through the motherboard and locked.
The cooler should not wiggle if you nudge it.
----------------how to mount the stock Intel cooler--------------

The stock Intel cooler can be tricky to install.
A poor installation will result in higher cpu temperatures.
If properly mounted, you should expect temperatures at idle to be 10-15c. over ambient.

To mount the Intel stock cooler properly, place the motherboard on top of the foam or cardboard backing that was packed with the motherboard.
The stock cooler will come with paste pre applied, it looks like three grey strips.
The 4 push pins should come in the proper position for installation, that is with the pins rotated in the opposite direction of the arrow,(clockwise)
and pulled up as far as they can go.
Take the time to play with the pushpin mechanism until you know how they work.

Orient the 4 pins so that they are exactly over the motherboard holes.
If one is out of place, you will damage the pins which are delicate.
Push down on a DIAGONAL pair of pins at the same time. Then the other pair.

When you push down on the top black pins, it expands the white plastic pins to fix the cooler in place.

If you do them one at a time, you will not get the cooler on straight.
Lastly, look at the back of the motherboard to verify that all 4 pins are equally through the motherboard, and that the cooler is on firmly.
This last step must be done, which is why the motherboard should be out of the case to do the job. Or you need a case with a opening that lets you see the pins.
It is possible to mount the cooler with the motherboard mounted in the case, but you can then never be certain that the push pins are inserted properly
unless you can verify that the pins are through the motherboard and locked.

If you should need to remove the cooler, turn the pins counter clockwise to unlock them.
You will need to clean off the old paste and reapply new if you ever take the cooler off.
Clean off old paste with alcohol and a lint free paper like a coffee filter.
Apply new paste sparingly. A small rice sized drop in the center will spread our under heat and pressure.
Too much paste is bad, it will act as an insulator.
It is hard to use too little.

----------------------------------------------------------------------------------

 

[Dadrian Daedalus]

Its a generic aftermarket cooler with a backplate and an alumunium heatsink,not the stock intel hsf.And i am also using a generic chinese mainboard as the msi g31 board that i had earlier conked out sometime ago and i couldn't find any decent mobos to serve as its replacement.My ambient temps are around 32 C.

This generic mobo has an AMI bios and it doesn't include any setting for cpu power management such as speedstep,c1e etc,thus my cpu runs at its max frequency ie 2.66 ghz all the time,which could be causing the heating issue.

acc. to intel temp guide thats available in this forum,the Tcase temps are apparently irrelevant but its considered safe as long as the temps stay below the max Tjunction limit for any particular cpu.Also in the same article it was mentioned that ideally the tjuction temp(that can be measured using utils like coretemp etc)should be kept below 85 C

So as my cpu temps are staying within the low 70s,is it a good idea to continue using the pc in its current state?

 

[geofelt]

32c. (90f.) OUCH!
All cooling starts with the ambient temperature and goes up from there.
You are doing fine, considering.
Keep on using it as you are.

 

[Dadrian Daedalus]

Yeah today the weather is rather hot and humid.

I could buy a better aftermarket cooler with heatpipes, but it would only add to the overall cost of the system.

As this pc is quite old, i dont wish to spend much on its upkeep.

 

[CompuTronix]

... My ambient temps are around 32 C ... acc. to intel temp guide thats available in this forum,the Tcase temps are apparently irrelevant but its considered safe as long as the temps stay below the max Tjunction limit for any particular cpu.Also in the same article it was mentioned that ideally the tjuction temp(that can be measured using utils like coretemp etc)should be kept below 85 C

So as my cpu temps are staying within the low 70s,is it a good idea to continue using the pc in its current state?

Dadrian Daedalus,

I'm the author of the Intel Temperature Guide your read. Let me reassure you that Tcase is more than "apparently irrelevant"; Tcase is definitely irrelevant.

As geofelt has already pointed out, 73°C is a safe temperature, but he's also absolutely right about your ambient temperature. The International Standard for "normal" room temperature is 22°C or 72°F, so you're 10°C above normal, which makes all your computer temperatures, including your Core temperatures run 10°C above what they would be in a normal environment.

You've already read this in the temp guide, but for the benefit of others, here it is again:

Intel processors have two thermal specifications. The "Datasheets" show both, but the "Product Specifications" website only shows one. For Core i 6th generation and earlier, the website shows "Tcase". This includes your Core 2 Q9400, for which the website shows 71.4°C, and is the reason why you're concerned.

This specification is highly misleading because Tcase is not Core temperature; it's IHS temperature. Intel doesn't spell this out in plain language, which is why Tcase has been confusing users since 2006. Tcase is a factory only lab test using engineering samples with a "thermocouple" sensor embedded in the center of the Integrated Heat Spreader (IHS).

Intel's intended purpose for providing a specification for Tcase is primarily for developers of aftermarket cooling solutions. The CPUs in our computers don't have a sensor for IHS temperature, which is why there's no software utilities to monitor it, so Tcase is irrelevant. Also, keep in mind that laptop CPUs don't have an IHS. Since the cooler is seated directly on the silicon Die, there's no Tcase specification for laptops.

The other specification, which is the one we need to pay attention to, is "Throttle" temperature. As geofelt also pointed out, for the Q9400 it's 100°C. This is the Core temperature limit at which the processor will reduce Core speed and Core voltage to safeguard against thermal damage. This specification is also called Tjunction or "Tj Max", which is shown in monitoring utilities such as "Core Temp".

For Core i processors that are 7th generation and later, Intel stopped using Tcase in 2017 on their Product Specifications website, and instead switched to "Tjunction". This appears in the Datasheets as "Tj Max", which means "Temperature Junction Maximum".

The consensus among well informed and highly experienced reviewers, system builders and expert overclockers, is that it's prudent to observe a reasonable thermal margin below Tj Max (Throttle temperature) for ultimate stability, performance and longevity.

Here's the nominal operating range for Core temperature:

Core temperatures above 85°C are not recommended.

Core temperatures below 80°C are ideal.

Your Core temperatures at 73°C are quite safe, so relax and enjoy your rig!

CT

 

[Dadrian Daedalus]

Thanks for the exhaustive guide and in depth explanation.

 

[SamirD]

Such an interesting set of data. Makes me really feel good about the systems I've got running 40c or under in an 80F room. Even under max load the highest these cpus will hit is 55c. And the only mod is to simply set the cpu fan to 100% by pulling the pwm pin on the fan header. And you can put it back in if you want to reverse the mod. I've never been comfortable with higher than 60c temps, but according to the guide there's still quite a bit of headroom.

Still, running this hot also stresses the other components on the motherboard as well as whatever else is in the case or nearby (like the ram), so I wouldn't run it that hot unless I had to.

Right now my x3360 Dell 330/380 hybrid is running in a similarly hot 94F room (it's 80F in the winter), and is still running well below 70c with the fans at 100%. For longevity, I would try to get the temps down.

 

[william p]

Now that you've told me that your system is a Dell Opti 380. If it's the MT size you can just get a Dell 0NC466, or 0DG168 Delta AFC1512DG fan. Prices vary greatly but they can be found for$10 or less sometimes. It replaces the original fan and housing. A little velcro and duct tape will do it. It runs off of the MB fan header. 150x50mm and 259cfm. It was used in workstations to cool 2x 130W Xeons. These can all be found for scrap prices if you look around enough. You might add some small heatsinks to the VRM MOSFETS.
https://www.ebay.com/itm/Genuine-De...445462&hash=item2aec367e0e:g:PYwAAOSwBWJbUhWB

With a BIOS swap I'm running the 120W X5470 Xeon in mine. 8GB DDR3 1066 and a GTX1060 3GB.
That fan with the old Pentium4 D9729, or the Opti 780 /mid tower T9303 heatsink (T9303 is better) will cool anything you can run in that, and it's quiet also. Twice as much airflow, and less noise.
https://www.userbenchmark.com/System/Dell-OptiPlex-380/1942
https://www.bios-mods.com/forum/Thread-OptiPlex-360-380-760-780-960-Xeon-LGA-771-E0-1067A-Microcode
https://www.delidded.com/lga-771-to-775-adapter/

 

[SamirD]

I'm not the OP and I think the OP just has a normal motherboard/hsf setup, but thank you for the dell part numbers for the heatsink. I know I need to get one before I put a 130w p4 in the gx520 that is still running. Even with the fan 100%, I think it would be too hot.

Noise doesn't bother me a wink as I'm usually remoting into these machines from elsewhere. So I set every fan I can to 100%. Performance > Noise.

Tapemodding and bios modding is more than I want to do on my machines. I'll max them out to whatever they can take, but that's about as far as I go. 'Bolt-ons only' if you will.