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by TD-Linux 4126 days ago
The main power draws of these systems will probably be the monitor they are attached to, the older PSU inside, and the hard disk. Keep in mind that for a RPi based solution, you still need to provide all of these. The tiny PSU needed for a RPi will probably be quite efficient, so maybe count that one out.

Also, as great as the RPi 2 is, I still don't think it is the same class as these machines, which have a 3x clock cycle advantage, plus much wider CPUs. For web browsing, this is going to matter way more than 4 cores.
1 comments
sitkack 4125 days ago
P4s have a horrible stall happy pipeline, the RaspPi has a decent GPU, I'd call it even. For a school environment and a good minimal window manager, the new RaspPi would be excellent for web browsing.

> I haven’t tried any normal desktop applications (other than Chromium), but I’d say the Pi 2 is finally worth considering as an full-fledged educational computer (i.e., beyond the introductory toy stage).

from http://taoofmac.com/space/blog/2015/02/07/1200

With a newer monitor and the current generation raspberrypi, it should powered directly from the USB hub in the monitor. With a bolt through VESA mount, a wifi dongle and netbooting off an NFS, a rapidly deployable Raspberry Pi school lab should be easily doable.

Yeah, this. http://www.adafruit.com/product/1320 PiBow VESA Mounting Layer Plate

Monitors I would look at are (needs HDMI, speakers, internal USB hub):

  http://www.newegg.com/Product/Product.aspx?Item=9SIA6R42AH7073
  http://www.newegg.com/Product/Product.aspx?Item=N82E16824116141
Finding the perfect monitor (internal powered usb hub) for the right price point is difficult, the device that needs to get built is a VESA case for the raspberry pi that has a NEMA 5-15R input and AC pass through, a USB powersupply for the RaspPi and a power switch that turns both the rasp and the monitor off.

DC in is nice, could run the lab off batteries or direct solar for off grid installations.

The problem is the software configuration for the NFS bootserver and making the netboot images.

Someone should make a VM image that can netboot a cluster of Raspberry Pis with a choice of roles (scratch, web browsing, quake 3, etc). With remote mounted home directories (served from ZFS, for snapshots).

One modification I'd like to see for the raspberry pi is better sleep support. I don't know if the SoC could do it, but if it could go into extra low power mode, possibly powered by a supercap, it could wakeup on external events (like an RTC) and not take any power from the USB.

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