Power consumption in desktop computers

[Anton Alin-Adrian]

Martin Cracauer wrote:

>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.
>
>
>  
>
Transmeta processors and transmeta-based systems are famous for their 
blinding low-power consumption.

Alin.