Some of the best SSDs, specifically the PCIe 5.0 drives based on the Phison PS5026-E26 controller, have been crashing instead of thermal throttling when operating without a cooler. However, it is worth noting that all of the impacted drives are designed and marketed to specifically be used with a heatsink, so the conditions that expose the thermal shutdown will not present themselves if the drives are used correctly (in accordance with manufacturer specifications).
Initially, only the Corsair MP700 exhibited this behavior; however, it's now become apparent that the issue is more widespread and affects other Phison E26-based SSDs that are designed for heatsinks when they are used without heatsinks attached.
German news outlet Computerbase discovered that the Seagate FireCuda 540, Gigabyte Aorus Gen5 10000, and Adata Legend 970 also suffer from the shutdown issue. It was to be expected since the PCIe 5.0 SSDs utilize the same Phison E26 controller. The FireCuda 540, Aorus Gen5 10000, and Leged 970 are still on firmware 22. Seagate hasn't gotten back to Computerbase when the new firmware will be available, whereas Gigabyte promised that it'll arrive "soon."
To recap: the issue only occurs when you use a PCIe 5.0 SSD without cooling. When the drive gets too hot, it shuts down to protect the SSD controller, NAND, and data. This shouldn't be an issue if the PCIe 5.0 drive is adequately cooled by the included heatsink or the M.2 heatsink from the motherboard. Regardless, Phison has released a new firmware (version 22.1) that ensures the PCIe 5.0 SSDs throttle — instead of just crashing, which can lead to data loss.
Firmware 22.1 introduces link-state thermal throttling that essentially reduces the PCIe interface speed — for example, dropping from PCIe 5.0 to PCIe 4.0 or even PCIe 3.0 to lower the temperature of the physical layer (PHY) without throttling the processor clock. This will obviously impact the PCIe 5.0 SSD's performance, but it should also keep it from engaging a shutdown to protect the integrity of the SSD controller. According to Computerbase, the thermal threshold on the new firmware 22.1 is 85 degrees Celsius.
In the beginning, the Crucial T700 didn't have the issue. The PCIe 5.0 would throttle until the drive operated at hard drive speeds but didn't shut down thermally. Computerbase performed more tests on the Crucial T700, and it showed similar failures, so the drive may also need the firmware 22.1 update.
Under the new firmware 22.1, Phison E26-powered SSDs should still provide an acceptable level of performance at high temperatures. Without a cooler, the Corsair MP700 delivered sequential read and write speeds over 10 GB/s and 2 GB/s, respectively. Remember that it's a safety measure in case temperatures get out of hand, and you should always use a cooler with your PCIe 5.0 SSD.
Edit: 7/21/2023 3:45pm PT: Clarified that these SSDs are specifically designed to be used with a heatsink.
