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 the 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 get warm enough to start throttling.


With heavy writes, the drive will start throttling when temperature exceeds 71°C. The throttling is not much and happens after almost 10 minutes of heavy writes. Part of the reason why the drive doesn't get so hot is that write speeds are relatively low, so the controller doesn't have that much load and stays cooler.

Thermal Image & Hot Spot

We recorded a thermal image of the running SSD as it was completing the write test. The hottest part reached 87°C.