As described at Bungie Support Forum threads 237011971 (NVIDIA) and 237140332 (AMD), as well as innumerable other threads on various forums.
TL;DR: The solution seems to have turned out to be temporarily underclocking the GPU Memory. I turned it down (from 1250MHz) to the same as the GPU's core speed (1050MHz) and that was enough to fix it.
Confounders, specs, and other bonus info:
- I solved this on
- Destiny 2 build:
78322:D2_ProdRetail:349
[early Steam build] - OS: Windows 10_1903_18362.418 [Microsoft KB4517389]
- GPU: AMD Radeon HD 7870 GHz Edition [Pitcairn]
- Driver 26.20.13003.1007 (non-ReLive), Settings 19.9.2 ["Latest Recommended" as of posting]
- Foxconn DX58M01/0R849J, i7-920, 3×4GiB DDR3-1333 [Dell XPS 435 MT]
- Destiny 2 build:
- I keep vsync and Framerate Cap OFF, including the via the GPU vendor setting toggle; these were noted as potential solutions as well online; though I can't give a good datapoint, I think they were off beforehand. But you should probably do the legwork and report back in the comments. (TODO: if I run across the "Sixx" mission, resolve)
- On the topic of AMD GPU management software: just setting a Destiny 2 Profile probably won't work; I never actually got the Radeon Gaming (Per-Game) Settings to work. There's lots of people online complaining about the per-game settings being thoroughly broken, so just use the Global OverDrive temporarily and call it a day.
Update: years later, applying this same trick fixed a system-level poweroff that happened after an hour or two of Overwatch. I thought I was going to have to replace my PSU or something, but just doing this fixed it instead!