Reddit mentions of Fujipoly/mod/smart Ultra Extreme XR-m Thermal Pad - 100 x 15 x 1.5 - Thermal Conductivity 17.0 W/mK

The new version says Gen2 on it. It makes full contact to the chip, is made differently (better quality - smoother texture), allows easier access to the microSD, and allows users to see the LEDs on the board. I also recommend a different pad if you're going to overclock; I use the Fujipoly Ultra Extreme XR-m Thermal Pad (I use the 1.5 size, but other users have reported using a 1.0).

Order from Amazon @ https://www.amazon.com/Flirc-Raspberry-Case-Gen2-Model/dp/B07349HT26

Or order from their official site @ https://flirc.tv/raspberry-pi-case-gen2

Order the extra pad @ https://www.amazon.com/gp/product/B00ZSJR1ZK/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

> https://www.amazon.com/Fujipoly-mod-smart-Extreme-Thermal/dp/B00ZSJR1ZK/ref=sr_1_2?ie=UTF8&qid=1495760301&sr=8-2&keywords=fujipoly+thermal+pad

> This is what I put under the heatsink.

I think 1.5mm is too thick, and I don't think ultimate thermal conductivity is needed, i guess the stock pads are good enough except that one or two are usually not touching the heatsink. Btw some have used K5 PRO viscous thermal paste; some pads are also putty-like and may be rolled thinner like dough before use.

The XPS 15 heat problem is elsewhere, in the VRM area! The issue is that the latter is not cooled actively. Unfortunately, there are several reports that just adding pads doesn't help enough, and that driving a lot of heat to the case bottom with quality pads actually makes things worse! In one successful mod, small heatsinks and also some pads plus a recycled copper plate detached from the case bottom were added to the VRM mosfets, but the key thing was to redirect some cooling air to the area and redo the air sealing. In some other thin laptops with fast GPUs and CPUs, this is taken care of with additional heatpipes from the mosfets, but it is not clear if some could be added here (with a good outcome and less hassle).

I didn't realize they were anything else colored blue. I am talking about this

https://www.amazon.com/mod-smart-Fujipoly-Extreme-Thermal/dp/B00ZSJR1ZK
It has a thermal transfer of 17w/mK The pads you're using right now are only rated for 1.7w/mK. The as5 are rated for 6w/mK and dropped my pch temps by ~30C for a 1.5mm thick piece.

Also how much space is there in that indent? If there's enough putting a copper shim would add even more benefit than any foam but if you have not even 1mm thermal foam would be best. The biggest thing you're doing is trying to move the heat off of the SOC. Since you're trying to move heat from the heatsink to the shell and give the heat more area to disperse a higher transfer rate will help. Now no pad is as good as a copper shim but if you don't have the space the artic pads are a good compromise.

I cut some the size of my pch and it's temps dropped from 80-90C to 45-55C. I had plenty of space so I went with 1.5mm thickness but the post you reference says there's only a 1mm gap so you gotta do what you gotta do.

P.S.
I may end up getting an XD+ from you modded once money becomes more plentiful.