The Linux Kernel Power Problems On Older Desktop Hardware
Phoronix: The Linux Kernel Power Problems On Older Desktop Hardware
As mentioned last week, a plethora of Linux power tests are on the way now that we have found an AC power meter with USB interface that works under Linux and we've been able to integrate nicely into the Phoronix Test Suite and its sensor monitoring framework. In this article is one of the first tests that have been completed using this power-measuring device as we monitored the Linux kernel power consumption for an old Intel Pentium 4 and ATI Radeon 9200 system for the past several kernel releases. Even this very old desktop system looks to be affected by the kernel power problems.
Something looks very wrong here...
First: Graph says milliwatts. I suspect that's a mistake, or you've just discovered a pretty amazing system.
Second on the first graph:
I don't see it. The way I read that graph is that in .32 and .33 the desktop was not stepping down the power, and was going full bore all the time. In .34 this power management was introduced for the desktop. Then it looks like, from .35 onwards, the stepping up was made more sensitive to increased performance needs, going to full power. This would be to prevent people experiencing stutter, or poor experience with the system stepping up and down constantly.
In terms of the power regressions that we have been tracking down, they are confirmed by this test.