2019 MBP 16 VRM Cooling Mod
Saturday, October 3, 2020 5:17 PM
2019 MBP 16 VRM Cooling Mod
TL:DR Applying some thermal pads to the VRM components of the MBP significantly helps reduce fan noise and allows CPU/GPU to run at higher frequencies. This fixes a problem I could not solve with software.
This mod addresses high fanspeeds whilst also addressing another 'issue' that I faced; low clockspeeds on CPU and GPU despite having low temperatures in gaming loads after 20+ minutes.
This cooling mod non-destructive and can easily be removed before manufacturer service/resale.
I've previously posted about high fanspeeds when using external displays. I've also written a guide to improve gaming performance by alleviating the thermal throttling with ProcessLasso.
MBP 16 2019 - i9 2.4GHz 64GB 5500M
~300MHz GPU, 1.4GHz CPU constant after warming up (Battlefront 2)
Now ~850MHz GPU, 2.2GHz+ CPU
With heatsink and slow fan >900MHz GPU, 3.4GHz+ CPU
Heatsink resting on the bottom casing of the laptop
Passive load - programs open, in a teams call https://i.redd.it/35obx5oqc4151.png
Fans are automatically maxed
Passive load - programs open, in a teams call https://imgur.com/LW9Xxhx
Fans are automatically at ~50% speed
What does this mod solve?
The root cause this solves is high VRM temperatures (Best guess as there are no VRM temperature sensors that I can read). This is a fairly well known issue on similar laptops that I have not seen anyone address on the MBP 16.
What this mod does not solve
You won't see improved performance for shorter bursts, my CB20 score is basically identical at 3459 vs 3412 (before) within what I consider tun to run variance
Thermals for the CPU and GPU should stay roughly the same - There may be less heat due to increased VRM efficiency
The centre back on the bottom of the computer now gets really really hot, too hot to touch so not something you should do something like edit videos on your lap
Edit: The upside of this is that resting this hot surface on a small heatsink with airflow can lead to even more performance
What does the mod involve?
Final result image: https://imgur.com/szN31ZY
Before shot for comparison (Thanks iFixit): https://d3nevzfk7ii3be.cloudfront.net/igi/yvxkmgnPVDVXNi4A.huge
Thermal pads were cut and applied to the MOSFETS and Inductors of the VRM circuitry. I used thicker pads ontop of the MOSFETS so that I could place thinner pads flat across the Inductors and padded MOSFETS.
I did not pad the heatpipes coming from the CPU and GPU as I don't have temperature issues with them
Thanks to /u/wcasdf padding both MOSFETS and Inductors seems to be required for prolonged sessions without throttling
I used a Silverstone M.2 thermal pads I had lying around, the pack came with 1.5mm and 0.5mm pads, both of which I ended up needing. They're rated at 4W/mK which is below the 6W/mK recommended in this XPS 15 mod guide https://www.ultrabookreview.com/14875-fix-throttling-xps-15/ but seem to work fine.