Thermal Throttling

Due to the compact form factor, M.2 drives usually lack the ability to actively cool themselves, typically 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 drive without additional cooling. 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 older SSD benches because we're using a different case and an AIO watercooling unit, so there's very little airflow inside the case.

Reads

Writes

The SN770M will throttle very quickly when heavily, loaded. For a portable console this is an edge case though, because it will never reach such high speeds for long durations.

Thermal Image & Hot Spot

We recorded a thermal image of the running SSD as it was completing the write test. The surface temperature of the heatsink reached 100°C, which is a reasonable choice for maximum allowed temperature. The drive's sensors reported like 93°C at the same time, so a little bit optimistic.