Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 25 Dec 2003 22:46:09 -0500
From:      Martin Cracauer <cracauer@cons.org>
To:        freebsd-hackers@freebsd.org
Subject:   Power consumption in desktop computers
Message-ID:  <20031225224609.A5326@cons.org>

next in thread | raw e-mail | index | archive | help
Hi,

those who followed might have noticed I was shopping for a notebook to
replace some of my desktop system.  To make it short, the notebook
vendors all pissed me off so good that I'm not going to get a notebook
(details on request) so I am going for other options.

Here is what my powermeter thinks my desktops are using with various
options:

System 1 ("wavehh", FreeBSD-4-stable):
- 1300 MHz Celeron
- Asus P2B board
- 3x 256 MB ECC modules
- 2x Intel 82855 fxp cards
- 3.5" Floppy 
- Promise PCI IDE controller
- Matrox G-400 (G-450?) 32 MB dual-head
- 35772MB <IBM-DPTA-353750> 
- 76345MB <MAXTOR 6L080J4>
- DVD-ROM <JLMS XJ-HD165H>
- CD-RW <32X10> at ata1-master WDMA2

Base power consumption with all drives: 99 watts
- No drives connected: 82 watts
- CD-Writer and DVD each take 1 watt when idle
- Maxtor disk takes 8-10 watts
- IBM disk takes 6-8 watts
- replacing the G-400 with some random plain S3 saves 4 watts
- forgot to measure what the fxp cards draw, but they get pretty hot,
  I assume it is not neglectable


System 2: "libber", Linux-2.6.0 and Win2K (yes, that's supposed to
become my FreeBSD-current system when I figure out why the CD-writer
broke on my move):
- Asus A7V600 Via KT600
- AMD Athlon XP 2500+ 1.83GHz
- 1x 512 MB non-ECC module
- ATI Radeon 7500 LE 128 MB incl ventilator
- Maxtor 6Y060P0 60 GB drive
- TOSHIBA DVD-ROM SD-R5112 (DVD-R writer)
- Adaptec 2940 with 3 SCSI CD-ROMS, picked up for $1 each on MIT
  swapfest
- TV card (model escapes me right now)
- 8139 Ethernet (doesn't get as hot as the fxp cards)

NOTE: this is the new Athlon core, this CPU takes less power than
e.g. the 2600+ and 2400+ which are based on the old core.

Base system with all drives: 	148 watts
- DVD writer idle: 		  2 watts
- 3x SCSI CD:    		 20 watts (ups...)
- harddrive			  5 watts
- no video card: 	        -23 watts
  (not sure the system goes into proper startup with no video)
- replace ATI card with G-400	-15 watts
  (16 MB card, not the save card as above)
- TV card out			 -6 watts
- SCSI card out			 -1 watt
- Realtek 8139 out 		 -1 watt

Harddisk activity: find / -name laksjfla:		 adds 1 watt

When Linux is driven with "make CPU halt calls when idle" the 148
watts go down to 136 when the system is idle, and up from that by 25
watts on drystone munching.

Remarks:

I assume that you can build a pretty nice powersaving box if you use
one of the Intel chipsets with 852/855 GM onboard video.

I am surprised the harddrives take so few power, but the numbers are
clear.  I was near replacing them with notebook drives, glad I
measured.

Don't pick up 10 year old hardware on flea markets if you want to save
power :-)

My old 20" Hitachi superscan Elite 751 takes more than twice the power
than the new el-cheapo MAG 19".

For some reason the AMD box draws about 5 watts when turned off.
Power supply change may be a good idea.


-- 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Martin Cracauer <cracauer@cons.org>   http://www.cons.org/cracauer/
 No warranty.    This email is probably produced by one of my cats 
 stepping on the keys. No, I don't have an infinite number of cats.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20031225224609.A5326>