|Dan Langille||Aug 26, 2005 2:42 am|
|David Landgren||Aug 26, 2005 7:55 am|
|Doug Hawkins||Aug 26, 2005 8:39 am|
|Frank Altpeter||Aug 26, 2005 11:09 am|
|Kevin Oberman||Aug 26, 2005 3:54 pm|
|Jeremie Le Hen||Aug 26, 2005 4:20 pm|
|Philip S. Schulz||Aug 26, 2005 5:37 pm|
|Dan Langille||Aug 30, 2005 12:20 am|
|Ulrich Spoerlein||Aug 31, 2005 2:51 pm|
|Philip S. Schulz||Aug 31, 2005 5:57 pm|
|M. Warner Losh||Sep 2, 2005 1:33 pm|
|Subject:||long flight; need battery power!|
|From:||Dan Langille (da...@langille.org)|
|Date:||Aug 30, 2005 12:20:39 am|
On 26 Aug 2005 at 8:55, Kevin Oberman wrote:
In September, I'll have a couple of long flights. I'll be using my IBM ThinkPad T41 to catch up on some long delayed FreshPorts enhancements. Apart from charging whenever I can, I'm afraid I'll get only about 140-150 minutes from my battery.
Apart from buying a second battery, any ideas?
This gets a bit long, but I've been spending a lot of my spare time testing this stuff and it's proven interesting.
What version of FreeBSD are you running? V6 has a lot better power management than V5 and current is better, still. If you are running V6, get the powerd from HEAD and use that or just keep the CPU fairly slow.
This is what I'm using: FreeBSD laptop.unixathome.org 6.0-CURRENT FreeBSD 6.0-CURRENT #10: Fri Jul 15 23:37:23 EDT 2005 da...@lux.exampel.org:/usr/obj/usr/src/sys/LAPTOP i386
'sysctl dev.cpu.0' will show (among other things) the available performance settings. Please remember that these are 'pseudo-frequencies' obtained by combining actual CPU clock settings with throttling and not just actual clock speed changes.
Wow.. .lots in there:
$ sysctl dev.cpu.0 dev.cpu.0.%desc: ACPI CPU dev.cpu.0.%driver: cpu dev.cpu.0.%location: handle=\_PR_.CPU_ dev.cpu.0.%pnpinfo: _HID=none _UID=0 dev.cpu.0.%parent: acpi0 dev.cpu.0.freq: 350 dev.cpu.0.freq_levels: 1400/22000 1225/19250 1200/18000 1050/16500 1000/14000 900/13500 875/13750 800/10000 750/11250 700/11000 625/8750 600/6000 525/8250 500/7000 450/6750 400/5000 375/5250 350/5500 300/4500 250/3500 225/2250 200/2500 175/2750 150/2250 125/1750 100/1250 75/750
You can use several tools to see the actual CPU speed. I use the gkx86info2 plugin for gkrellm2.
If you are just editing, a very low speed is the winner. Turn off powerd (if you are running it) and just set he CPU to the lowest performance available. If you are compiling, bump it up to the lowest native CPU speed. For debug, it depends, but I suspect you want lowest, again.
I plan to be doing a combination of coding and running database queries. But I'll try to do some testing before I go...