Does temporarily suspending an idle chip reduce its lifetime?

Question

Nowadays many chips, especially CPUs for portable devices can decrease the clock speed or even suspend for short periods of time to save power. This is great.

Now when a chip reduces power consumption it dissipates far less heat and cools down. Typically a device executes commands in bursts. You start a heavy app and the device's CPU runs on full load for say 15 seconds and warms up, then you might use the application without triggering its CPU-intensive functions for a long period of time, then the CPU load decreases greatly and power saving mechanisms supsend or downclock the CPU and it cools down. Then you trigger some CPU-intensive function, the CPU runs on full load for 10 seconds and warms up, then cools down.

Does frequently warming up and cooling down a chip in the manner described above have negative effect on the chip lifetime?

Answer 1

It possibly would, however the effect would be negligible relatively to the usable life of a laptop, technology wise.

Besides, running hot consistently would probably be almost as bad (if not more).

I'd be more worried about electromigration in your CPU (technically around, I guess...) when it's running on full juice than it cooling down and heating up.

Answer 2

I have never personally seen data on a processor's expected lifetime. As long as the part is kept within the datasheet specifications (no overclocking), I would expect at least 5-10 years out of a part. It is more likely that something on the motherboard would go out before the processor.