• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

Accurate Core Temps

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.


New Member
Jun 6, 2001
Great article. I'm planning to monitor core temp using the same technique. I opted for the Enermax HDD Cooler w/ 2 thermal sensors (I'll use one for core and one for case temperature). It's cheaper than buying 2 individual sensors plus you get the plastic bezel to mount the LCDs in a 5-1/4 inch bay.

I wondered just how accurate this method would be, thanks for providing the answer.
If it wouldn't be too much trouble. Can you tell us what article you are talking about?
Here's the thermistor strip. You can see the excess Capton on the tip, that needs to be trimmed back.

I'm thinking of doing the exact same thing. I'm just having a hard time leting go of the money. ?? I'v been looking for a setup like this for a while and the price on this isn't that bad considering the led displays are allready installed in a 5 1\2 cover. Sorry dremel tool not this time :( As accuracy goes I'm thinking this is going to be a lot better than the system temp given by the thermal probe that's built into my motherboard. Getting a faster more accurate reading is my whole reason for looking for a new temp probe setup. Temps mean life or death to me and I need a good setup. So I need someone to kick me in the head and tell me what to buy.

Great article. It helps A LOT thank you.
I got a Soltek mobo that came with the same sensor but no read out, nice touch back when I got it. One issue though. Remember the talk of swirling air currents of the Sorb giving false readings, well this technique (vs. the drill method) may allow additional cooling of the probe that varies by heatsink design. Thermo-engine comes to mind. I always thought a sheet of paper with a die cutout installed between the cpu and sink would negate that factor or at least prove it a non-issue.
Trust me. with only a .015 inch slit for the air to get into, You will not be troubled by collateral cooling of the sensor. Besides, I spec'd the sensor in tandem with a drilled type K thermocouple and their readings were identical, to the tenths of a degree.

Fair enough, just a though because I observed some differences, although only tried the Sorb relative to itself (with and without paper). The rest is speculation.
On mobo chipsets, it is a little more interesting since they dont have a raised core to butt up against. After I lapped the heatsink on my Northbridge and applied arctic silver, it has never been warmer than skin temperature when I checked it, so I have not worried about monitoring the temperature continually.

It was while attempting the same procedure with the onboard thermistor that I fried my 1g TBird. The thermistor must have been just thick enough to prevent proper seating of the HSF, and within 30seconds, zap. Needless to say, I am a bit leery of attempting this.
Oh poopoo! I know how it feels Stool. Can't wait for the Palomino.
I thought I had covered that clearance issue adequately in my article. If you two veterans didn't catch that, then I'm worried other, less experienced folks will not also. Wish I had not lost the accompanying pictures. They would have had more merit embedded in the article, than in this thread.

I liked your article so well that I ordered one. Haven't gotten it yet.
I can't tell from your pics if you cut back the capton to the T/C metal or not.
I'm assuming it has metal to metal contact with core.
Do you push the T/C in after the HSF is installed?
Maybe not, since you used hot glue, but if it's a temporary installation, could you use a stretched rubber in the .015 clearance to hold the T/C in place with the HSF installed?

I was trying to thin the probe end of a indoor/outdoor digital temp indicator, and broke, separated the T/C weld joint. Would you happen to have a way to fix one, or good place to order just the thermocouple itself?

Thanks - Sammy
Let me tell you all about it...
I originally clipped off the excess capton on the tip of the strip, very carefully with a sharp pair of diagonal cutters. I didn't want to crush the thermistor, so I only cut it so close. The fact that there was still a small amount of capton left, on the tip, got to bothering me, so I put a fresh blade in my X-acto knife and tried to slice it off. The Jewelers loupe kept falling out of my eye and I tried to do it without it.
If anyone has one of these units and the display is bad, let me know. I have a display without a thermistor.
I ordered a new one and it should be here by Tuesday.
In the mean time, I am back to using the one I drilled the hole in the HSF base for. Dumb Dumb Dumb!

Yes, to be absolutely safe, you should push it in to butt up against the core with the HSF already in place. That way, you can rest assured that it will not impede the mating of the HSF base and the core. You can tell if you are making it all the way to the core by retracting it and looking closely at the tip. There will be a smidgeon of AS on the tip from where it exuded out around the perimeter of the core. Put it back in and once you feel confident that you have it where you want it to be, put a dab of hot glue on the zip cord, right where it passes out from beneath the edge of the HSF. I tacked mine to the mobo. Another fellow had a good idea of taping it to the ceramic to immobilize it. You would want to use a tape that is resistant to heat making the adhesive break down. IE, not Masking tape, not Duct tape, Not Scotch tape. This goes without saying, but make sure the tape you use is very thin. You only have .015 inch to spare under there.

Hoot - thanks for your experience - doesn't make me feel quite so bad about crushing mine.
I've got to find a place to just buy the T/C tips.

This might sound like a rubber band fetish, but I do find a lot of maybe unconventional uses for them.

I could never keep a jewelers loupe in place, even with bags. I use the part of a small magnifier in a stand used for things like stamps, etc., and unscrew the magnifier part, which is similar to a loupe AND then I used a rubber band to hold it on a pair of glasses - spectacles type. End up with a focal distance of only about 5 inches

I was thinking that once you push the T/C probe under the HSF and against the core, you could stretch a piece of rubber band enough to squeeze it between the HSF and T/C, and when you relax it, it would hold it in place without undue force on the HSF.
Personally, I would not put anything between the baseplate of the HSF and the CPU ceramic surface that even remotely requires compression to function, such as rubber. I would not want to fight the retainer clip or springs to keep that baseplate in firm contact with the core, even slightly. There are virtually limitless options for immobilizing that sensor. It's just a matter of finding what solves your particular challenge with a minimum number of opportunities for failure.
Too bad I didn't measure the thermistor value before I trashed it. I do know it is less than the 10k ohm one that radio shack sells. Besides, the R.S. one is too thick to fit. Perhaps an email to Enermax will get you a replacement unit. The replacement one I ordered is actually a dual unit already mounted on a 5-1/4 bay escutcheon. It costs $20.00 plus s/h from KD Computers. Considering single ones go for $14.99 plus s/h, it seemed like a good deal.

Radio-Shack is supposed to carry those thermistors. Well, the one I bought my thermometer from, had them anyway. Maybe things are different up here in Canada. So I bought an extra one just in case. Only thing is, I was in debate about cutting off the original thermistor and just using the spare from the start to bypass all the cutting/ whittling/ shaving down of the one that comes on the thermometer. The spare comes with no insulation what so ever. But being the sucker for punishment I am, I spent an afternoon shaving down the original. Having an old slot1 celeron, I had no problems sliding it in. But I did notice something, apprently I didn't buy the same thermometer as the rest of you. The ones Hoot has pictured, only came with a thermistor encased in metal, at my RS. Oh well, the only difference I geuss is I'll have to find a niffty way to mount it. Thanks for the great article Hoot! Solved my problem of wondering it the Asus PC-Probe really is 10°C off. In my case it is, not exactly 10°, but somewhere close. all this time I've been trying to get temps under 30°@ idle, and I've already been there all this time. Sitting at 27.7°C right now.
Hoot - your caution about using rubber bands is certainly understandable. I just usually don't like to use tape unless there's no good alternative, and you're right, there are countless other retention methods.
I tried a couple of different sizes and I think the force is negligible.
I just got my enermax today and was pleasantly surprised at how thin it is.
I trimmed the tip down pretty easy using fingernail clippers that worked great.
I'm thinking of a way to heat and flatten the heatshrink tubing, rather than cutting it back, and without damaging something of course.
That's a good idea. I've "molded" heated heatshrink many times. The callouses on my fingers from soldering actually protect them quite well. ;D

Here's what you do. You got both leads coming out of the strip with heatshrink on them. Then you have a second piece of heatshrink over both of the smaller pieces. Remove the bigger piece. then, heat the two smaller ones with a cigarette lighter or match until they're soft. Not too much, so as to unsolder the leads. While they are hot, squash them and hold until they are cool,in the same plane as the strip.

With the HSF in place slip in the strip and see if the squashed heatshrunk leads will fit. if they don't, then it's back to trimming them back. If they do, you're all set. Whattaya think?