The initial ramp-up from the SoC’s idle temperature is rapid, though it must be noted this test took place in an ambient temperature of nearly 25°C. Once the SoC hits 70°C after around 25 seconds, the temperature rise slows; by two minutes it is around 77°C; by three minutes it’s around 81°C. As is to be expected, these readings — taken from an internal sensor located on the GPU portion of the SoC — are higher than the external package temperature measured during the thermal imaging test.
Interestingly, the first thermal throttle operation isn’t captured until around four and a half minutes into the test, and a quick glance at the rest of the graph shows why: where earlier Raspberry Pi models would tend to hit a throttle point and stay there the Raspberry Pi 4 is instead spending as little time as possible at its throttled clock speed of 1GHz, returning to 1.5GHz as quickly as it can. With the measurements being taken at a rate of one per second but the CPU’s frequency switching taking place on a much shorter timescale, it’s likely the Raspberry Pi 4 was throttling earlier but for too short a time to be captured.
This benchmark clearly demonstrates additional cooling is going to be a must-have to maintain top performance for workloads including sustained CPU activity over the four-minute mark— but for those who are using the device as-is, expect to see less sustained throttling than in previous models after the thermal throttle point is reached.
Claramente que não é uma opção para todos, mas para quem anda a tentar extrair a performance máxima... É sempre interessante de ver que é possível.
