Phison's response mentioned TechPowerUp, so I also checked out their review:
https://www.techpowerup.com/review/corsair-mp700-2-tb/
"The uncooled drive shut down after 86 seconds of reads, a power cycle was needed for it to restart."
"With a fan, no thermal throttle during reads."
"The uncooled drive shut down after 55 seconds of writes, a power cycle was needed for it to restart."
"With a fan, no thermal throttle during writes."
"Corsair ships the drive without a heatsink, it's your own responsibility to use your motherboard's M.2 cooler or buy an aftermarket thermal solution. I'm not convinced that this is the best solution, especially when other Gen 5 previews have shown heatsinks of various sizes on competing M.2 Gen 5 drives. In our thermal testing of the bare drive, without any airflow in the case, which is a worst-case, we saw thermal throttling during reads after 90 seconds at full speed (or ~500 GB total transferred) and after 55 seconds of writes (~240 GB total transfer). While these durations seem short, you have to consider the immense amount of data transferred in such a short duration. For the vast majority of users I'd even say that there's no need to go crazy with cooling, 99.99% of the time you will not move enough data to make the drive throttle; and you also need a data source or target that can match the speeds of the MP700. What makes things problematic though is that once thermal throttle is reached, the drive will stop working until a power cycle. No, it will not slow down until it cools off, it will simply disappear to the rest of the system and never come back, even when cooled down. This looks like a firmware issue to me that should be fixable."
"If you absolutely must have the fastest SSD, then the MP700 can be a good choice, but make sure you put some cooling on it."
And the original Phoronix article:
https://www.phoronix.com/review/corsair-mp700-pcie5
"...in practice this drive struggled under Linux with real-world workloads."
"When not adding an after-market heatsink, the MP700 was quick to exhibit EXT4 file-system errors."
"While the Inland TD510 was equipped with a large heatsink with fan, the Corsair MP700 was not. However, it is mandated. Initially for testing I planned to first run it without any after-market heatsink just to see how warm it would get under operation... That idea quickly proved not to be wise."
"I only made it to installing Ubuntu 23.04 and installing various benchmarks before the EXT4 file-system began spewing errors and went into read-only mode. When rebooting the system, at least FSCK was able to correct all of the EXT4 file-system errors. But, again, within a few minutes and just setting up the system for testing, there were more EXT4 errors."
"After attaching the basic passive heatsink for the NVMe SSD that came with the ASRock motherboard and running EXT4 FSCK a last time, after that point the file-system errors went away. So it would appear that you definitely will want to plan on using at least a large passive aluminum heatsink for cooling the MP700."
"Across these workloads the Corsair MP700 was quite toasty even with the passive aluminum heatsink while the Inland TD510 with its included active heatsink had on average a lower drive temperature by about 16 degrees."
"With the Corsair MP700 running into EXT4 file-system errors when simply setting up the test system without any extra heatsink, I'd be quite frightened to use this in production even with the extra heatsink. Paired with the mixed results -- namely performing poorly in real-world workloads aside from sequential synthetic tests -- and the higher PCIe 5.0 NVMe SSD drive prices with being new to market, I'd hold off on upgrading to any PCIe 5.0 NVMe SSD storage yet."
