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, reporting in at more than 90°C. As temperature increases, throttling gradually increases as well, which is a more reasonable approach than sudden drops when a certain temperature limit is exceeded. Overall, the throttling is quite significant, but you have to consider that this a 240 GB drive, so you'll have to fill up most of its capacity to reach a point where throttling becomes relevant.

Thermal Image & Hot Spot

We recorded a thermal image of the running SSD as it was completing the write test. The hottest part reached 103°C - at that point in time, the SMART thermal sensor on the SSD reported a temperature of around 95°C.