This table shows the power consumption of some of the computers I own. I use a domestic electricity meter that was certified for use in billing customers to measure this. Any inaccuracies in the measurement will
correspond to inaccuracies in electricity bills of people who use such computers.
Before anyone asks, I am not interested in contributions of data, I believe that doing tests with a different meter or in a different country with a different supply voltage will diminish the accuracy of the results. Also I will provide minimal analysis on this page (the numbers should allow you to perform your own analysis).
Before I started such tests I had significant problems cooling my house in summer. Based on the results of these tests I made changes such as replacing the Compaq 1GHz Athlon machine by an IBM 1GHz P3 machine for a small server I run, this saved 49W of power, 49W of power which mostly ends up as heat makes a significant difference in a small server room when running 24*7!
All the machines below apart from the SMP machine are workstation class machines, they don’t have ECC RAM and their PSUs are designed for small load. The SMP machine has a PSU designed for a desktop machine (I couldn’t easily obtain any other type). If it had a PSU designed for server use it would draw more power.
Unless otherwise noted all machines were idling while running Linux (idling while running DOS uses significantly more power).
The summary of this table is, P3 is a great CPU for power to computer power ratio, the P4 isn’t too good, and the Athlon sucks badly – don’t run an Athlon server if you have heat problems!
|Thinkpad T20 500MHz P3 512M 30G IDE||10.7W|
|Cobalt Qube AMD K6-450MHz, 128M RAM, 10G IDE||20W|
|Thinkpad T41p 1.7GHz idle at 600MHz, screen on and battery charged||23W|
|Compaq SFF 800MHz P3 512M 10G IDE spun-down||28W|
|Compaq SFF 800MHz P3 512M 10G IDE||35W|
|Compaq 800MHz P3 128M 10G IDE||38W|
|IBM 1GHz P3 256M 30G IDE, idling||38W|
|HP Pavilion 513A Celeron 1.8GHz, 384M RAM, 40G IDE||45W|
|HP Pavilion 513A Celeron 1.8GHz, 768M RAM, 2*80G IDE + 46G IDE||58W|
|Compaq 1.1GHz Celeron 512M 40G IDE idling||46W|
|HP/Compaq Celeron 2.4GHz, 512M RAM, no hard disk||43W|
|HP/Compaq Celeron 2.4GHz, 512M RAM, 300G IDE||50W|
|NEC Pentium-E2160 1.8GHz, 1G RAM (1 DIMM), 160G S-ATA||52W|
|Packard-Bell (NEC) Celeron-D 2.93GHz, 512M RAM, 2*20G IDE||75W|
|Compaq 1.5GHz P4 256M 20G IDE, idling||78W|
|Compaq 1.5GHz P4 256M 20G IDE, installing||85W|
|SMP 2*P3 1GHz, 1GB RAM, 2*U160 SCSI 18G disks idle||81W|
|SMP 2*P3 1GHz, 1GB RAM, 2*U160 SCSI 18G disks disk busy||99W|
|SMP 2*P3 1GHz, 1GB RAM, 2*U160 SCSI 18G disks CPU busy||130W|
|SMP 2*P3 1GHz, 1GB RAM, 2*U160 SCSI 18G disks CPU and disk busy||136W|
|Compaq 1GHz Athlon 256M 20G IDE idling||87W|
|NEC Pentium-D (920) 2.8GHz, 1G RAM, 160G S-ATA||98W|
|White-box Athlon XP 1700+, 768M RAM, 2*80G IDE + 46G IDE||110W|
Here is the Computer Related Power Use page  (for switches, filters, and other things).