Thermal Throttling

Due to the compact form factor, M.2 drives lack the ability to actively cool themselves, usually having to rely on passive airflow instead. All vendors include some form of thermal throttling on their drives as a safeguard, 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, installed in the M.2 slot between the CPU and VGA card, while it's getting hammered by non-stop incoming writes. A first test run, to create a baseline, shows temperature and performance with a 120 mm fan directly blowing on the tested drive. In a second run we report thermal performance of the completely uncooled 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 degrees Celsius (measured using SMART).

Results from this test setup are not comparable to our 2019 SSD bench because we're using a different case, and a CPU cooler that generates some airflow around the CPU socket.

Reads

Writes

There's quite a lot of thermal throttling when heavily loaded, without the heatsink. Once the heatsink is added, throttling is much less pronounced but still visible in our testing.

Thermal Image & Hot Spot

Without the heatsink (first image) the drive reached around 90°C. Adding the heatsink (second image) reduced the surface temperature to 72°C, but the drive under the heatsink still got hot enough to thermally throttle.