We had a power meter lying around my new office and a different variety of stuff from last time , so here's some more power consumption numbers.
First, for a random assortment of stuff:
| Allied Telesyn FS705-LE 5-port Ethernet switch | 3 watts |
| Allied Telesyn FS750 16-port Ethernet switch | 7 watts |
| Sun SunFire X2100 1U server, powered off | 6 watts |
| SunFire X2100 powering on | 130 watts and a lot of noise |
| Dell 1907FP LCD displaying stuff | 26 watts |
| Dell 1907FP in powersave with no signal | 2 watts |
Next, for a 2.4 Ghz Intel Celeron on a VIA CN400/PM800 based motherboard in a more or less generic case with a more or less generic 40Gb IDE drive, running Ubuntu Linux:
| powered off | 3 watts |
| idle at the Ubuntu Gnome login screen | 75 watts |
| CPU usage at 100% | 120 watts |
Finally, for one of my main M2N4-SLI machines:
| powered off | 3 watts |
| in the BIOS's hardware monitor screen | 122 watts |
| idle, either text or graphics | 98 watts |
| in the Gnome screensaver | 120 watts |
| streaming disk reads from one drive | 125 watts |
| streaming disk reads from two drives | 137 watts |
| one core busy with a CPU soaker | 128 watts |
| both cores busy with CPU soakers | 155 watts |
| both cores busy and streaming writes to a software RAID-1 | 158 watts |
| both cores busy and one drive doing streaming reads | 158 watts |
| both cores busy and both drives doing streaming reads | 162 watts |
The streaming disk reads took about 10% of the (dual core) CPU for one drive and 21% for two drives, all in system time according to
vmstat
and
procinfo
. Streaming writes use a significant amount of CPU all on their own, so I only ran them with the CPU soakers active.
Interestingly enough, the power figures suggest that writing to the software RAID-1 filesystem (which was actually LVM on top of a RAID-1) was not actually driving both disks simultaneously. Possibly the Linux kernel bursts writes back and forth between the drives.
Sidebar: the boring hardware details
The M2N4-SLI machine that I measured has an Athlon 64 X2 4600+ CPU in an ASUS M2N4-SLI motherboard, 2GB of memory, two 320GB Seagate SATA drives, an Enermax Liberty 500 watt power supply, and an ATI X800 GT PCIe graphics card. I'm not going to try the ATI binary drivers this time around, so I have no figures for that.
I don't know what exact hardware the Celeron box is built from; it is a more or less generic box that we happened to have lying around.