Thermal Throttling

Due to the compact form factor, M.2 drives lack the ability to cool themselves and usually have to rely on passive airflow instead. As a safeguard, all vendors include some form of thermal throttling on their drives, which limits throughput once a certain temperature is exceeded.

On this page, we will investigate whether the tested drive has such a mechanism, how high temperatures get, and what effect this has on performance. We will test the drive in a typical case, in the M.2 slot between the CPU and VGA card. A second data point shows the result when a 120 mm fan is blowing directly on the tested drive. Each of the charts has time moving from left to right, with the blue line displaying transfer speed in MB/s and the red line showing the temperature in °C (measured using SMART).


In a pure read scenario, the drive doesn't throttle at all.


During the write tests with a fan, we see no performance drops. When the drive is without cooling, its temperature will climb quickly. Once it reaches 80°C, write performance will drop down to around 300 MB/s and stay there for as long as the drive's temperature is at 80°C. Higher temperatures don't happen due to these reduced write speeds. Still, consider that 80°C is only reached after a constant full-speed write of 100 seconds. At the drive's speed of 450 MB/s that means you'd have to write 45 GB of data without pause to get the drive to throttle.

Thermal Image & Hot Spot

We recorded a thermal image of the running SSD as it was completing the write test. The hottest part reached 80°C, which nearly exactly matches what the SMART thermal sensor on the SSD reported.