Power Requirements |
created:17 Aug 2008 @ 01:47 am edited:03 Jul 2009 @ 05:05 pm |
Partly because I recently bought a little power efficient computer and wanted to see how much its really saving me, and partly because it's always bugged me.
Overview of my setup: While at Uni
I currently have 3 computers and a laptop with the following specs:
|
Desktop kanga | CPU: | AMD 3000 x2 @ 3Ghz |
| RAM: | 4GB Corsair (4 sticks) | |
| Hard Disk: | 80GB - OS | |
| Hard Disk: | 2x 320GB (RAID 0) - Data | |
| Optical: | DVD /- RW | |
| Graphics: | ATi x1950 Pro | |
| PSU: | Corsair HX 620W | |
|
Laptop roo | CPU: | Intel Core Duo T2300E @ 1.66Ghz |
| RAM: | 1GB (2 sticks) | |
| Hard Disk: | 120GB | |
| Optical: | DVD /- RW | |
| Graphics: | ATi Mobility x1300 | |
|
Server rabbit | CPU: | Intel Pentium E2160 @ 1.8Ghz |
| RAM: | 4GB Corsair (4 sticks) | |
| Hard Disk: | 80GB - OS | |
| Hard Disk: | 2x 160GB (RAID 0) - Data | |
| Hard Disk: | 7x 500GB (RAID 5) - Data | |
| Optical: | DVD /- RW | |
| Graphics: | Intel 82945G Express | |
| PSU: | Corsair HX 620W | |
|
Mini PC eeyore | CPU: | VIA Eden @ 1.2Ghz |
| RAM: | 1GB Corsair (1 sticks) | |
| Hard Disks: | 250GB | |
| Optical: | DVD /- RW | |
| Graphics: | Heh... don't make me laugh | |
Between the 3 desktop machines I share 3 screens (that all act as one when using kanga :D)
| Left: | Dell E177FP | 17" Flat Panel |
| Middle: | Dell SP2208WFP | 22" Flat Panel |
| Right: | Dell E176FP | 17" Flat Panel |
I also make use of a Dell Axim x50v, Cambridge Audio Azur 340A, Old (but 4.1) PC speakers, a very basic 100Meg Switch and a Netgear WGT624 wireless access point and router.
How to Measure
I constructed a test cable from a bit of flex with a 13A plug on the end, an old socket and wall mount and some wire gripsAs we are measuring Amps, the ammeter has to be wired in-line.
Having wired everything up I took the readings. I measured the amps, as they are directly proportional to the voltage and wattage. As we know that the voltage is 230v RMS, we know that Watts = Current * 230
For the less electronically minded, the calculation (how kind!):
Power (Watts) = Current (Amps) * Voltage (Volts)
What to Measure
I will be measuring the power draw when the devices are "off", idle (on and not doing anything), and under load (e.g. playing a 3D intensive game).The Results
Ahh, the bit you've all been waiting for. Well, to be honest I was hoping that eeyore would use around 20W maybe 25W so I was a little suprised at its result. However the other computers I thought were very acceptable compared to what I expected.Have a few graphs:
First off, a graph showing the power required by each device by itself. The items labeld 'Phil' belong to my neighbour who was in on this project.
Graph 1
Next, a graph showing the power used by complete systems.
Graph 2
Each dataset includes different devices:
Eeyore includes my middle screen, eeyore, the router and my amp.
Attie includes all my computers, screens and amp and network infrastructure.
Kitchen includes all of the devices needed to use our family computer (including the modem)
And again for Phil's Computer.
Afterwards
As you can see from the graphs, despite the fact that rabbit has 10 hard drives, kanga still takes more power. This is due to the processor (rated at 130W!) and graphics card in kanga.Yes... well done, my naming convention comes straight from Whinnie the Pooh. My PDA is Wol, and my phone is Piglet. But no, I have no Whinnie...