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Power [Consumption] - Laptop as NAS/media server

Posted: Thu Apr 02, 2009 4:05 am
by truckid
Hi,
I have a few old components and am thinking of going the the route of using an old laptop with an attached external drive to serve as a NAS but was wondering on what kind of power consumption I can expect.

I have an old Acer Aspire 3610 - Celeron 370 1.5G, 1.5gb RAM, 60Gb HDD - the screen was damaged, so I ripped it off. It will be used as a headless unit, possibly Windows Home Server or some flavour of Linux.

I also have a WD3200JS 320Gb SATA HDD, for which I was thinking of buying a USB/eSATA Enclosure.

It would be used primary as a NAS, for my Squeezebox and PS3, but also as a print server and maybe a VPN so I can securely connect when I am away. - This flexibility is why I want to set this up, rather than buy an external Nas box.

I know its a very vague question, but what kind of power consumption could I expect, if left on 24/7. The laptop has no display,no battery (always on mains) and I would disable Wireless (connected via ethernet only). Unfortunatley, the bios is very limitted, Wake On Lan would be a nice to have, I am not sure if its possible to load a custom bios with extra features such as this.

Im trying to workout the cost of leaving these devices (laptop/external HDD) on all the time. I know without some kind of meter I can't get a precise output, but even a ballpark figure would be fine. I would greatley appreciate any advise/recommendations.

Thanks

Posted: Thu Apr 02, 2009 11:26 am
by jessekopelman
I don't think this CPU has Speedstep, so I could see the laptop using maybe as high as 35W-AC at idle. That is worst case, though. Could be as good as 20W. My 1.7GHz Pentium M draws 12W with the screen off, but Speedstep makes a big difference.

An external 3.5" drive is going to run you 10-15W-AC. Going with an external 2.5" drive you'd probably be down to 5W-AC. Going with a 3.5" drive like the WD GreenPower that automatically unloads the heads very aggressively could also get you down close the 5W-AC mark and get you lots of GB/$.

So depending on configuration, I think you are looking at a draw of anywhere from 25 to 50W-AC. My guess would be 35W, especially if you go with an energy efficient external drive. Even 50W is pretty good for a modern desktop build, so I'd say this is a good use of what you've got lying around. A couple of notes:

* I wouldn't expect the laptop to survive more than 2 years of this use case because it is basically the opposite of the designed function.

* Look into revoSleep and similar utilities to potentially shut down the external drive when not in use. In a 24/7 situation, saving that 5W when idle, via a free utility, is a nice win.

Posted: Wed Mar 03, 2010 6:41 pm
by expxe
jessekopelman wrote:I don't think this CPU has Speedstep, so I could see the laptop using maybe as high as 35W-AC at idle. That is worst case, though. Could be as good as 20W. My 1.7GHz Pentium M draws 12W with the screen off, but Speedstep makes a big difference.

An external 3.5" drive is going to run you 10-15W-AC. Going with an external 2.5" drive you'd probably be down to 5W-AC. Going with a 3.5" drive like the WD GreenPower that automatically unloads the heads very aggressively could also get you down close the 5W-AC mark and get you lots of GB/$.

So depending on configuration, I think you are looking at a draw of anywhere from 25 to 50W-AC. My guess would be 35W, especially if you go with an energy efficient external drive. Even 50W is pretty good for a modern desktop build, so I'd say this is a good use of what you've got lying around. A couple of notes:

* I wouldn't expect the laptop to survive more than 2 years of this use case because it is basically the opposite of the designed function.

* Look into revoSleep and similar utilities to potentially shut down the external drive when not in use. In a 24/7 situation, saving that 5W when idle, via a free utility, is a nice win.
Wrong.