Another Graphite Thermal Pad Test: Panasonic PGS

[ImperialKnightErrant]

I finally got round to testing the 500um graphite pads. It performed worse than the 100 and 200 um pads, over-temperature in OCCT in barely 2 minutes (see graph for performance). Which I guess is to be expected, given the extra thickness.

 

On balance, I think IC Graphite got it right with going with the 200um thickness pads. While 100um seems to perform marginally better, it is also much less robust to handle (easily bent). And Thermal Grizzly seems to get it right with respect to the thermal performance. Graphite pads are fine for everyday use, but definitely not for extreme overclocking or stress testing overclocked CPUs. 

 

In fact, I've kind of left the 500um in there, since the temps are about the same during regular use, 37-40C idle, 55-61C during gaming (with 29-31C ambient).

 

 

[Saccaed]

I'm still blown away by your results and plan to test an AIO on my desktop. Arctic MX-4 is the grease I normally use and for most of my tests was comparison grease. All my rigs are air cooled and both the OC desktop and OC laptop performed as good/better then better still with more mounting pressure. If AIO mounting pressure might generally be low, I wonder if things would change with a socket'ed AIO direct die contact mount. For whatever reason grease and maybe liquid metal might be the things to go with for you.

[T[]RK]

Just for the record... i upgraded my CPU to i7-3820QM and runned same test like before - AIDA64 CPU Stress Test for 10 minutes.

 

Here is results:

Room temp is 29°C (HOT!)

I didn't apply Kapton Tape around CPU die this time.

 

In Cinebench R15 i got 542 points, which is lower then i got with i7-3630QM (563) with ThrottleStop, but with i7-3820QM (and no Throttlestop) i hit almost 45W (CPU Package Power) and there was throttle. Maybe because dGPU hit 58°C... Can i exceed TDP limit?

 

Update: Yeah i can... another run.

 

Max Power: 45.5W

dGPU was 66°C.

 

[T[]RK]

Quote

This thread is quite old. Please consider starting a new thread rather than reviving this one.

No, i would like to keep data consistent AND keep it in one thread.

 

So, Panasonic have got two new products:

 

1. Multilayer PGS (ML-PGS?);

https://eu.industrial.panasonic.com/products/circuit-thermal-protection/thermal-protection/pyrolytic-graphite-sheet-pgs/Multilayer-PGS#overlay-context=products/circuit-thermal-protection/thermal-protection/pyrolytic-graphite-sheet-pgs/Multilayer-PGS

 

2. Thermal Storage Sheet (TSS).

https://eu.industrial.panasonic.com/products/circuit-thermal-protection/thermal-protection/pyrolytic-graphite-sheet-pgs/thermal-storage-sheet#

 

ML-PGS is basicly few layers of 0.025mm PGS with 0.05mm adhesive layer. This wasn't discovered before, but it's perform interestingly since it decrease hot spot size.

 

After some time use PGS in laptop i no longer sure that PGS should be "cut to die size". Heat from small die is concentrated on same small area. I think bigger PGS with adhesive layer which stick to heatsink may perform better (spread heat from small die to heatsink). ML-PGS is good opportunity to test this idea.

[Saccaed]

Your thinking may have legs. During my initial tests I tried a few different sheet sizes to try to determine if die size or larger than die size was better without noticing any differences. The Soft PGS has no adhesive though and the larger than die size test relied on building up the area around the die to push the PGS margin into the heat sync. High mounting pressure I imagine would still be critical in performance, but the better heat transport has me thinking about wrapping the entire heat sync portion in the Multilayer PGS(provided an adhesive backed version is available). After working with liquid metal and comparing, copper is plenty conductive enough to not be a choke point. Provided that contact area is limiting heat transfer when using Soft PGS, I've wondered what would happen if the entire heat sync portion was coated in the PGS material. The thermal storage sheet looks to me unlikely to be useful as a PC TIM; maybe, but there is no mention of better heat transfer. For something like a phone I can see useful applications as the device itself is often the heat sync and there are temperature considerations to keep everything withing safe operating limits. For PC cooling, there are no temperature considerations for anything but the cooled component as the heat syncs do not have any thermal considerations at the temperatures that any IC would run(less than 110C). The ideal TIM for PC cooling is one that heats immediately with the least delay and also efficiently transfers between IC and heat sync. If either solutions contact better that could cause better performance.

[falkin42]

I only joined to say thank you for this thread. I found it a month or two ago and thought it was useful then but to have y'all come back to it and continue making meaningful posts is just awesome.

I don't have much to add myself other than I'm planning a new cpu/motherboard/ram combo to upgrade my q9550 finally so I'm considering thermal interfaces. I think I'll get some PGS and see what's what. Not going to try any real overclocking until I can afford to water cool. Looking at https://www.arrow.com/en/products/eyg-s0909zlx2/panasonic a 90x90x0.2mm sheet for about $20. That multi-layer stuff is interesting.

[Saccaed]

If you feel like you can be careful enough, liquid metal is still far better even for the price. If your looking for something to experiment with, or it's a moderate system, PGS should work fine. If you want to overclock, liquid metal or icy diamond is the way to go. I wouldn't worry about a water cooler for overclocking(unless you have special considerations). Especially with liquid metal, temps can be managed just fine with a tower cooler(Noctua NH-U14S for example).

[T[]RK]

This thread is following more "research" path then actual use of PGS. It's very interesting product, especially on paper, but make it actually work as we need (replace completely thermal grease) is a big challenge. Especially with HIGH TDP products.

 

I think it will work and keep CPU "in spec", but this way (how to do it exactly) isn't discovered yet.

 

It's easy with LM: get it, apply it, assemble, run, enjoy temp drop. Not interesting because it already discovered.

 

Mix PGS and LM - now this may be interesting! Add PGS under CPU IHS - this is interesing (especially under Ryzen 3000 with it's small chiplets design).

[falkin42]

I'm not worried about using liquid metals; it's not my first build. I'm interested in the water cooling honestly for the fun of building it since I know I don't need it and at that point I'll definitely be using the best interface I can find. For now I'm just curious.

Anyway I'll leave it be, I generally lurk and only wanted to say I appreciate the reading material.

[Saccaed]

One thing I have been pondering is if the PGS material can be applied in a fashion like hydro dipping. Seems like if possible there can be some interesting applications. In particular I've been thinking that if the PGS material can be applied like hydro dipping it could be a great way to wick heat from gun barrels(I have an AR15 with free float and keeping it cool means more accurate shots). That's a topic I'm going to be exploring. Even if the gun cooling does not work out, if any progress is made I can see good use in car applications too(preventing under hood hot spots initially is what comes to mind). Stabilizing the material for temps well above 200C would also be nice.

 

@T[]RK Could be interesting to mix PGS and LM just to see how they interact. Do they react and cause material failure? How does the heat transference compare to the two materials when used separately.