Hi. I've been using OpenBSD on my netbook daily for a few months. I was using apmd with the -C setting. My netbook is slow and the battery life is important, so 800Mhz (apmd -C) or 1600Mhz (apm -A) is not a big difference for me.
Now I have a desktop computer with support for cpu speed scaling. In this case the options of apmd are very limited. If I use "-A" my cpu is always at 2700Mhz, wasting energy and heating my room (I live in the very sunny Extremadura :) ). If I use "-C", apm rarely raises the speed and the cpu is almost always at 800Mhz. This is important because when I open a web page with a lot of javascript, the browser is very slow. Also when I compile something with "make -j1", apmd doesn't raise the speed of my CPU, I need use "make -j4" for raising the cpu speed to 2700Mhz. I understand the problem with the limits of apmd. The developers can't generate a limits for each CPU and workflow. I've been playing with the values of PERFINCTHRES and PERFDECTHRES on usr.sbin/apmd/apmd.c and "checking" the changes of speed with "while true; do apm | grep cool; sleep 1; done". I'm using 20 and 60 respectively right now. Probably this values aren't the best values but are better than the defaults (for my CPU and workflow). The performance is very good and I can see the cpu speed raising and lowering. I've tested various values and 20/60 are a good compromise "performance vs energy consumption". In short, I have a suggestion for apmd. Add one option for to set PERFINCTHRES and other for to set PERFDECTHRES. Each user could to configure the behavior of "apm -C" on rc.conf.local. Example: apmd_flags="-C -I 20 -D 60". Obviously, "apm -C" would use the defaults if both options aren't used. The implementation is simple and it will not break any system. Unfortunately I can't code the idea (despite I've read the code), so I wanted share this with you. Some developer interested? :) Cheers. -- Juan Francisco Cantero Hurtado http://juanfra.info
