On 16.02.03, 20:37:43, Miles Nordin wrote:
> 
> Also, the power budgets in these machines vary dramatically.  Some

Certainly true even for backlit-color-LCD/keyboard type machines.
I had a Compaq 1080C for some weeks (half-VGA display, small keys),
that would last for about 1.5h under optimal conditions (no programs
running, no keys pressed, just sitting there; now I have a z50
(which is bigger, but has full-size keys and full-VGA display) that
lasts almost ten times as long.

> (like mine) have backlit screens that run for 1.5 - 5 hours depending
> on the brightness setting, off a rather chunky LiIon battery, almost
> like one of those Dell Everybooks with SpeedStep(r) Technology.
> Others have reflective LCDs like a Newton or a celfone/keitai and run

Are there HPCs with reflective displays and a keyboard with full-size
keys? That sounds like almost perfect, even if it were only B/W or
4bit grayscale.

> NetBSD for a week off cheapass alkaline disposable batteries.  If
> you're in the one-week crowd your ideas about power consumption must
> be totally different.
> 
> What REALLY eats battery like a mofo is 802.11b cards.

(what is a mofo?)

I personally found that that's not neccessarily true. I used to
run my z50 with a wired Ethernet (3Com 395TP or something), and
recently switched to WLAN. I find that the machine still lasts
around 14 hours with moderate network activity (X-session with
Webbrowser running over the link, IPSec-leaf-node-tunnelling). It
drains the battery faster on a heavily loaded network, I experienced
that on the Chaos Communication Congress in Berlin, where it would
only last 9 to 10 hours in the overloaded WLAN.

Btw, according to the specs average CF cards do not use significantly
less power than MicroDrives. IMHO the main point for CompactFlash
over MicroDrive is the CF's mechanical robustness. MD is quite
robust, as far as hard disks go (and, iirc, has a gravity sensor
that immediately parks the disk in free-fall to prevent damage from
the following impact.  Does that mean MDs don't work in orbit?) but
nothing beats CF with no mechanical parts.

As to the read/write cycles, it is true that in theory Flash memory has
a limited number, but most modern cards do internal load-balancing to
the cells (don't ask me how that is done) to spread out the write-cycles
more evenly. I don't have any figures if CF or mechanical hard disk is
more likely to fail given certain workload types.

On both types it is certainly a good idea to mount filesystem with
options "noatime, nodevmtime". to prevent frequent (write) accesses to
the disk, even if it's otherwise idle or only read.

> -- 
> Computer games don't affect kids, I mean if Pacman affected us as
> kids, we'd all be running around in darkened rooms, munching pills and
> listening to repetitive music.
> 		-- Marcus Brigstocke

-- 
Bernd Sieker

NetBSD short theme, for stickers and tattoos: NetBSD... Bitchin'!
		-- Mason Loring Bliss