On Tue, Oct 18, 2011 at 11:53:25AM -0700, Joe S wrote: > This isn't a problem and I'm not complaining, I'm just a bit curious > as apmd didn't save me as much power as I hoped for. I noticed that > apmd couldn't throttle my cpu in 4.9-RELEASE (amd64). However, since > March 2011, -CURRENT recognizes the K10 cpus, so I wanted to try it > out apmd on my HP Microserver. So I upgraded my system from > 4.9-RELEASE to a recent -CURRENT snapshot. When I run "apmd -C" > hw.setperf gets set to 0 and the hw.cpuspeed gets set to 800 MHz. That > was expected. I attached a Kill-a-Watt meter to my system to see what > kind of power savings I would experience with apmd enabled. I think my > expectations were a bit too high. I was only saving .5 watts when my > cpu was throttled down to 800 MHz from 1.3 GHz. I haven't seen many > posts on this subject, so I was wondering if the power savings of .5 > watts sounds normal, or if something is wrong on my end.
Sorry Joe, I'm not subscribed to misc@, marc.info is ro, I didn't see your message. I worked on K10 freq scaling for my laptop, indeed, it doesn't help much in terms of measurable power savings.. not as much as I had hoped it might. Playing with voltage settings may have helped, but it seemed risky.. no other implementation messages with it either. The effects are more noticable on laptops, but for desktops/workstatons, it's not really worth enabling apmd, just make sure you have decent cooling. -Bryan.
