Observations

[Ben Hall]

S.M.Kelly wrote:

> First, my CPU fan seems to run almost constantly.  My CPU is usually 
> fairly idle and doesn't seem to be running many active threads. This 
> makes battery life horrible.


I have an iBook 700, I've also noticed that Linux runs hotter (and thus 
louder) than OSX (or XP on an Intel laptop.)  There are many reasons for 
this.  For starters, the HD doesn't spin down nearly as much.  To fix 
this you can do several things:

- Install bdflush
- Fiddle with hdparm to set the sleep delay
- Use Ext2 or at least set the write times for the Ext3 journal for 
something quite large
- Disable any unneeded daemons (such as, I would argue, the cron and at 
scripts.)

I suppose throttling the CPU back would help battery life qute a bit.  
I'm not sure how this is done, but know it's possible.

Linux runs a lot of stuff in the background, any of these can wake up 
the HD.  With a lot of care, power management in Linux can be pretty 
much what it is on OSX or XP, but it takes a lot of fiddling.  FWIW, 
I've found the PM stuff for Apple HW to be lightyears ahead of the PM 
for Intel HW, it's one of the reasons I like the iBook so much as a 
Linux box.

> Second, Gnome uses a lot of RAM!  As I use Gnome, I see my RAM usage 
> steadily creeping up until it gets to nearly 95% of usage. (remember, 
> I have 512mb!)  When I use KDE, it stays around 30-40% usage.  I use 
> the same applications most of the day. (Xmms, Evolution, OOo, primarily)


Hmmm.. big surprise!  Yeah, probably just memory leaks/buggy software.  
Have you tried something lighter like FluxBox or XFce?  They are very 
useable, stable and make Gnome and KDE feel like dogs.  It's hard to 
kick FluxBox's tabs once you get used to them.

> Third, I NEVER have seen my 512mb swap file being used.  Does the swap 
> file only get used when your physical RAM is maxed?


Yup, this is normal.  It's also quite normal for Linux to always use up 
as much RAM as possible, it's just sitting there, so they might as well.

Cheers,

Ben