[Honeywell PTM7950 Phase Change Thermal Pads/Sheets] Application, Tips, and Results

[Adrian_Joachim]

@ajb

@Nickolas_Grigoriadis

Wow, looks like the chassis temperature is down about 2°C, just by moving heat more efficiently into the vapour chamber.
Nice!

Yay for thermal conductivity at the right place!

I would look at the red line and not at your irony

2 degrees of chassis temperature is not insignificant.

[Nickolas_Grigoriadis]

I don’t know why people thought it was irony.
lets say typical room temp is 22°C, at 36°C it becomes uncomfortable to be on your lap.
So you only really can afford the chassis surface temp to increase by 14°C before it becomes uncomfortable.
The graphs there showed that improving the thermal conductivity by the heatsink got rid of enough heat to buy you a significant comfort margin, which is not what I expected.

Enough that I am considering getting some PTM7950 to try on my old MSI notebook.

[Michael_Wu]

Yeah, for example the 2°C decrease in the yellow line from 61C to 59C is a decrease of 3.6°F (141.8F to 138.2F) for those that can relate to Fahrenheit. That might not seem like much, but it’s nice to know the increased thermal conductivity also leads to cooler internal chassis temps, which should cause cooler external chassis temps. Good for while using on your lap, and also a good thing for battery longevity. And also might be a big difference if used lightly on e.g. a bed where the vents may be blocked.

I personally did have to take a look at the chart again to see what you were talking about for the 2°C as that had maybe detracted away from the possibly more impressive 911°C drop on the red line CPU diode sensor. Maybe that was why, but I saw no irony and I’m glad you pointed out that detail! I’m sure others may have missed it as I did.

@ajb

I bought the PTM 7950 pad (30x20*0.25mm) over ebay for €11.52 inclusive postage (a Polish dealer delivered very fast to Germany within 4 days).

(emphasis mine)

Perhaps it was just a miscommunication? Idk, but hey from the other side of the world, and thanks for posting your results! Good info for AMD 7840U.

And we can all celebrate the wonders of PTM7950

Edit: whoops, 11°C drop on the red line not 9°C, I temporarily forgot how to do basic arithmetic

[respectable_username]

Thanks so much for re-testing! Great to hear there was very little/no change long term from the pad!

Though interestingly, this was my biggest take away:

@Michael_Wu

If you zoom in, you can see that there’s dust blocking the fins and yes, it doesn’t look like much. But little amount was causing an increase of 5-10C! I had already removed a ton of dust from the green boxes, so my temps must’ve been even much higher. I definitely noticed an increase in fan load/noise during regular usage (but let it be), and am confident it was the dust.

I didn’t realise just how much impact on thermals only a year’s worth of dust would have! If a significant thermal improvement can be had just from cleaning out the dust, that’s actually really good to know. Thanks also for providing such a good guide for how to access the fans for thorough dusting.

If y’all can come up with a suite of tests that you find useful, I might do my own test before and after dusting just to see how much dusting alone impacts thermals, before purchasing any new thermal interface materials. If such a large boost can be gotten for free literally just through cleaning, I consider that an absolute win!

My Framework hasn’t been my main workhorse as I have a separate work laptop, so there probably won’t be as much build up as somebody who does use it daily. But if even under those conditions the dust build up has an impact, then maybe having a 6-12 monthly laptop clean out would be a good idea? Am mainly thinking about just how many issues Old Laptop has with thermals which I litterally can’t fix because Old Laptop is stuck together with glue

Maybe a new thread for more generalised thermal testing based on different variable might be a good idea? There’s so many different variables and different interface materials it’d be interested to have a centralised place for folks to share their findings under relatively standardised conditions!

[Adrian_Joachim]

@respectable_username

If y’all can come up with a suite of tests that you find useful, I might do my own test before and after dusting just to see how much dusting alone impacts thermals, before purchasing any new thermal interface materials. If such a large boost can be gotten for free literally just through cleaning, I consider that an absolute win!

Set the fanspeed to some fixed value, the thermal limit to some fixed value and the power limit as high as it goes. The run a stress test and record the package power after some determined amount of time (and check it is actually at the thermal limit and not limited by something else, if it isn’t reduce the thermal limit and retry).

Imo that’s a pretty solid way to test relative cooling performance.

I did do this kind of testing between stock and ptm earlier in this thread over a range of temp limits and fan speeds (I also did the testing with lm but the results were within margin of error of ptm so I didn’t bother to update the charts).

Edit: Almost forgot, make sure you do it on the same surface, that makes a huge difference. Propping the back up just a little drops temperature by quite a bit at max fan so that’s a variable you’ll want to control.

[Adrian_Joachim]

@Michael_Wu

Also found this: I Successfully Disabled STAPM and Increased the Power Limit on my Matebook D!
Only skimmed it for now, but interesting. I think I saw these values set somewhere in the lotus-zephyr branch for the EC, so I think it might be possible to change it or ideally Framework allows disabling STAPM completely (at users’ own risk).

I think I may have gotten around it using smokeless, at least I managed to do 44W for 15min now which is a lot longer than I was able to do before (I’ll do some propped up testing later, may get even more from that). You could also just stay under 80C, which makes stapm tick up again but where’s the fun in that.

Also gonna have to make sure this didn’t make idle power worse

@Michael_Wu

A bit off-topic though, maybe we should branch this into a separate thread?

Mayhaps

[Adrian_Joachim]

Holy moly, after 1h doing 46W (temp limit 99, back of that laptop propped up, max fan) the keyboard isn’t even hot.

That cooling solution is better than I’d hoped.

[Michael_Wu]

@respectable_username and @Adrian_Joachim a general thanks and good info

For relative testing between thermal materials, +1 to this:

@Adrian_Joachim

Set the fanspeed to some fixed value, the thermal limit to some fixed value and the power limit as high as it goes. The run a stress test and record the package power after some determined amount of time (and check it is actually at the thermal limit and not limited by something else, if it isn’t reduce the thermal limit and retry).

Imo that’s a pretty solid way to test relative cooling performance.

and maybe setting the power limit to a fixed value to control for that, as well as accounting for starting temps.

I just created a separate thread and will branch the non-PTM7950 to there to keep things less noisy for others.

[Adrian_Joachim]

@Michael_Wu

and maybe setting the power limit to a fixed value to control for that, as well as accounting for starting temps.

You either test for temps at a given power or for power at a given temp, both at the same time does not make a ton of sense to me.

[Michael_Wu]

Oh to clarify, I meant test for temps at a given power, but by “accounting for starting temps” — ensure that the test starts at the material’s respective idle temperatures. E.g. wait 5 minutes to let temps get down to idle so that the thermal material’s temperature floor can be recorded. And then set a fixed power limit so that the temperature ceiling is locked to it.

That way, we have the floor temp (idle) and the ceiling temp (for a fixed power limit) for each material, and then those can be compared. Does that make sense?

Addendum: I think power at a given temp would also be a nice, quick performance measure!

[Adrian_Joachim]

@Michael_Wu

Oh to clarify, I meant test for temps at a given power, but by “accounting for starting temps” — ensure that the test starts at the material’s respective idle temperatures. E.g. wait 5 minutes to let temps get down to idle so that the thermal material’s temperature floor can be recorded. And then set a fixed power limit so that the temperature ceiling is locked to it.

If you test to steady state the initial temp should not matter.

@Michael_Wu

Addendum: I think power at a given temp would also be a nice, quick performance measure!

That’s pretty much what I did here

[Michael_Wu]

@Adrian_Joachim

If you test to steady state the initial temp should not matter.

Er I meant testing for the speed at which temperatures rise over time which would affect how long a processor could turbo for (or I think the max power and the duration it can be held).

I guess that should be separated out into it’s own test? So then we measure:

1. the duration in seconds and the max power from idle to thermal throttling (~100C) at max load
2. temps at a given power
3. power at a given temp

Though if in 1. the max power limit can be reached below the thermal throttle threshold (and/or if the processor can turbo indefinitely), then the measure would just be the temperature at that max power limit (equivalent to 2. and 3.)

To automate this simply, perhaps 1. can be skipped entirely. We peg the fan to max, run the initial heat-soak, then step through power by 1W increments and measure the respective temperature. Which is basically:

@Adrian_Joachim

That’s pretty much what I did here

Though with just that, we can’t gather how quickly temps rise from idle to throttle. Hm, is that even a valuable measure if we already have 2. and 3.? I kinda think no now :s

[Adrian_Joachim]

@Michael_Wu

the duration in seconds and the max power from idle to thermal throttling (~100C) at max load

at 85W power limit that’s really fast XD

This test has a bit more variables than I’d personally like.

@Michael_Wu

Though with just that, we can’t gather how quickly temps rise from idle to throttle. Hm, is that even a valuable measure if we already have 2. and 3.? I kinda think no now :s

May be interresting but that contains an unholy ammount of variables you need to controll for and even then not sure how useful it is.

[Nickolas_Grigoriadis]

Just an update. I installed PTM7950 on my old MSI notebook, and the difference is night and day. The fans spin up so much less now…
The notebook keyboard itself isn’t getting as warm as before either. A very noticeable change.
(I don’t have hard numbers to compare it to before unfortunately, but the difference is staggering)

I had to apply it twice as I had to thin out the pads for the gpu ram to allow it to make proper contact on the gpu as the PTM7950 is thinner than what was there before.

[GhostLegion]

So just letting everyone know of a not sketchy source for genuine PTM7950

PTM7950 Phase Change Thermal Pad

Reasonably priced too

[GhostLegion]

So I ordered the big size because I’m a dumb American who really ought to be used to doing metric conversions and omg, I’ll never use this all haha.

Granted, I wanted to do my Xbox along with my eGPU but I’m certain to have extra, enough for quite a long time I expect…anyone know the shelf life on this stuff? Pics for reference on what you get when you order.

[Michael_Wu]

Did the conversion, 200mm x 160mm is ~7.87 x ~6.30 inches. Busted out the tape measure and oh my that’s a lot

@GhostLegion

anyone know the shelf life on this stuff?

This page has a lot of information, including the PDFs in the TDS, SDS & Technical documents section.

In this document for Honeywell’s “pad format TIM” on page 2, it says that at room temperature at <65% RH (relative humidity) it has a shelf life of 12 months.

For PTM7950 specifically, here on page 2, with a storage condition of 19-24°C (that’s 66.2-75.2°F for us dumb American folks ), <65%RH, it also says it has a shelf life of 12 months:

Directly from Honeywell’s site it also says 12 months in the Specifications tab, and in the Thermal Interface Materials Electronics Brochure in the Resources tab on page 7, it says:

Shelf Life: 12 months (Storage condition on the package for directions)

Though I’m willing to bet those specifications are for precision usage and wouldn’t really matter too much in consumer usage a la our mainboards or your Xbox, because of my anecdata seeing how performance didn’t degrade after 19 months in my Intel i7-1165G7 mainboard. May be best to ask LTT support directly.

Edit:
oh yeah, I still have my almost 2 year old material from the first post in this thread (from ebuy7 and Alibaba). Been waiting to install it in my AMD 7840U for after I figure out a data gathering procedure. Whenever I get around to installing it, I’ll update, though I don’t have new sheets for comparison. Maybe I’ll purchase from LTT to support them. Or if someone else wants to do it, I’ll ship my aged sheets over for free! since I don’t think I’ll be getting to it for a while

[Chironjit_Das]

Bought mine from an Aliexpress store with a small set for under $5. Used about 25% of the provided amount on my 1260p. I have to say I’m another convert in this group as my laptop is noticeably quieter (didn’t do a before and after temp) even after running a stress test stress --cpu for about an hour.

Link to the store incase anyone wants a cheaper, smaller one:
https://www.aliexpress.com/item/1005004744337186.html?spm=a2g0o.order_list.order_list_main.101.1bfa1802AZP7hN

[JanW]

@GhostLegion

anyone know the shelf life on this stuff?

I bought some off E-bay. Seems genuine enough, but the merchand may have replaced the sticker. Mine says “Period of Validity: 3 years. Production date: 2023.11.25”

I peeled off the sticker, and the one underneath is in Chinese (I think) and mentions a date of 2024.02.15.

[Nickolas_Grigoriadis]

As I understand it, the whole point of this stuff is that its industrially rated, meaning should have a operational life of over 10 years. So that means a shelf life of that minimum, as long as it’s not contaminated.