I'm gonna add my 2-cents about RasPi power usage/drawn current measurements.
At idle I get 1.64 Watt (322mA at 5.09V
at login prompt on Arch, idle CPU, nothing plugged but power).
Below are some tests I made:
- 322mA ~ 323mA
- only power, no IO, (peaks at 350-390mA
when CPU solicited),
- only a couple PS2 keyboard & optical mouse plugged together on one USB port with an adapter (+30mA when mouse in use, +7mA when num lock LED on!),
- ethernet only,
=> CPU stress test with ethernet only with 'stress --cpu 8 --io 4 --vm 2 --vm-bytes 4M --timeout 20s':
current jumps from 375
at idle to 435-465mA
- Mouse&KB + ethernet and idle CPU.
(Another test showed that the couple mouse and keyboard alone draws 28mA when idle, to 80mA when mouse in use + 7 to 8mA per keyboard LED when on.)
- ethernet and composite video (compared to 375mA
without video composite),
- Mouse&KB + composite video + ethernet at idle CPU (not sure how KB+Mouse only adds 12mA, when it's supposed to be 28mA, oh well),
=> CPU stress with this setup:
current jumps from 389mA to 440mA
(peaks @ 480mA
- CPU idle, LXDE/X11 on!, composite video, ethernet, PS2 KB&Mouse together on one USB port,
=> Peaks at 475mA ~ 515mA
when: mouse in use + CPU stress, composite video, LXDE/X11 on, ethernet,
That was still not enough to blow up my 500mA (fast melting) fuse. I'm sure I can managed to do that by adding a 70mA flashdrive on the remaining USB port though. Didn't try it.
Note that the values above are with mouse idle unless specified (the optical red thingy goes a bit down and draws significant less power when the mouse is not moved: Logitech).
Also note that the peaks are fast displayed values on the multimeter and are probably quite higher for very very short whiles since the multimeter displays short averages. The other values are constant/fixed values.
Also it's interesting to note that after a "sudo halt", the raspberry pi displayed "system halted" as expected, but still draws 435mA constantly with ethernet, Mouse&KB, composite video, 424mA without the Mouse&KB, and then 372 without ethernet (just video)! Those are higher values than when the PI normally operating with corresponding setups.
During the tests, my HTC charger went from 5.15V to 5.01V. From now on I'll use a Y-USB cable that can provide 1A on my computer (2x 500mA): http://goo.gl/Z4IR9
. It seems to be totally enough for current but drops to 4.70V at times though. But that's just my computer, and the PI seems to be okay with that.
Anyway, was just taking a look to have an idea what a headless RPi server would need, and it's 375mA to 500mA for the use I'll make of it (to be somewhat sure that it's enough).
So we're still quite below 700mA but you guys knew that before my tests.
Hope all this helps a bit.