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.

Results

MBP 16 2019 - i9 2.4GHz 64GB 5500M

Gaming

Pre-mod

  • ~300MHz GPU, 1.4GHz CPU constant after warming up (Battlefront 2)

Post Mod

  • 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

Work

Pre-mod

Post Mod

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

Potential downsides

  • 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.