Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Low Energy Computing => Topic started by: djh on May 18, 2015, 11:13:46 AM

Title: I need a new computer (or two ...)
Post by: djh on May 18, 2015, 11:13:46 AM
We're coming to the end of building our new house and my old computer is even older than it was when we started building! So I think I should be looking for a more efficient one. I've paid no attention at all to computer technology for the past couple of years or so, so I've no idea what I should be buying and would appreciate some help.

I haven't really worked out a requirements spec so here's a top-of-the-head list.

I'm looking for a desktop machine - I like proper keyboards and screens and being able to plug in extra disks or whatever comes along next. I run Linux - presently Suse but maybe I'll go with something else - I run XFCE or LXDE or even ICE, I'm not interested in fancy grahpics effects and I like traditional windowed desktops. I do want to be able to run video properly though, without the hesitations I get on my old machine. I'm fairly lazy and leave work half-finished on the screen, so the machine tends to stay on most of the time - does sleep or whatever it's called work properly in Linux yet?

I'm looking for something quiet that doesn't use a lot of power but is reasonably priced.

As well as acting as my desktop machine, I need something to act as a media server though exactly how much use it will get I don't know. I'll also need something to log data from the house and maybe do some control, but I've currently got a Raspberry Pi that I can use for that and just use my desktop as backup.

Any ideas on off-the-shelf products? Or what CPUs, motherboards, power supplies etc?

Title: Re: I need a new computer (or two ...)
Post by: davec on May 18, 2015, 12:00:37 PM
Why not have a think about some Network Storage... we have a Netgear ReadyNAS that we use to hold all the 'big' data. It's basically a wee Linux box hosting a mirrored filestore. As such, it can run media servers for you (e.g. we use it as an iTunes server) and other stuff (e.g. I keep my SubVersion repositories on it).

Because of the NAS, we can get away with medium spec second hand computers... there's a company near us who have a good line in refurbished Dell's, Compaq's etc.

Title: Re: I need a new computer (or two ...)
Post by: billt on May 18, 2015, 12:19:51 PM
I use a couple of Intel NUcs. They're small, low power consumption and quite capable for most uses. The NUC i5 2450 is my main computer and with a Dell U2713 high res monitor makes a good iMac replacement at half the mac cost.

Only disadvantage is that it has a small fan which can be audible at high CPU usage.

Title: Re: I need a new computer (or two ...)
Post by: davec on May 18, 2015, 01:21:15 PM
PS: if you haven't already, and the walls of your new house are still open, consider running some cat-5 cable about the place.

Title: Re: I need a new computer (or two ...)
Post by: djh on May 18, 2015, 01:57:04 PM
Thanks for the ideas.

I'm not looking for an old secondhand computer - I've already got one of those :)  I'm looking to see what's current.

The NUCs seem to be typical of one school of thought at the moment, although some of their competitors manage without a fan. I guess the Intel's are probably better specced? But I'm not sure whether the approach is right for me. I don't need something squeezed into a sandwich box or designed for living room appeal. I think I care more about expansion/replacement of parts, but maybe I'm wrong to worry about it.

There's a bunch of Cat-5e running in the walls, thanks :)

Title: Re: I need a new computer (or two ...)
Post by: jonesy on May 18, 2015, 03:23:02 PM
Well, I gave up on desktops as they eat power, and I've always hated laptops, for the reasons you gave.
However, 2 years ago I bought the latest i3 laptop, with 17" screen (400).  It uses 35W flat out.  My desktop used 120W + monitor. Portable, so easily hidden, and when I'm programming for friends, I simply take it, and all tools with me in a convenient package.  Would never go back to a desktop.  I have a 2nd monitor which I sometimes use.  Under W8 I leave all apps open and hibernate, then it's all there when I turn it back on the next day.
Having just spent 200 on a new 15" Celeron laptop for the OH, it's got nearly the same speed as it's quad core vs my 2 and takes about 20W.  If my 2yo breaks tomorrow I know what I'm buying. Very little to repair on a PC mobo now anyway - it's all integrated.
I've got a 1TB usb drive on USB3, which is plenty quick enough.  Again, nice and portable. I can plug it into the router if I want a NAS, or there are plenty of adaptors.
I use a PIC for data logging of around 40 parameters which are pushed to places like thingspeak, pvoutput and xively every minute, and they take care of backup, graphing etc. You could setup the PI to do that easily. I use a pi as a audio server+hifi codec, which gets turned on as needed, with a 300G disk for storage (500+ CDs in wav)
In terms of power, my only permanent IT load is the router at 9W, and the PIC at 1W.
It would be pretty difficult to find a bad power supply as the industry is pretty regulated; what uses the power is the CPU/peripherals etc. From some pretty extensive testing I did on cat iii/iv/v power supplies last year showed that some of the cat v psu with very low 'standby' when left plugged in, but not used, are less efficient on load than some cat iii, but they were all pretty good >85%. But this figure varies with load.  I would question any savings on expensive power supplies, but that's just me.

Title: Re: I need a new computer (or two ...)
Post by: dhaslam on May 18, 2015, 04:28:17 PM
If you use a desktop computer with a  mini ITX  case you would have something similar to  a laptop in size and  power usage but  with proper keyboard and screen and would be upgradable to some extent. 

Title: Re: I need a new computer (or two ...)
Post by: knighty on May 18, 2015, 04:33:10 PM
do you want to build your own or buy one pre-built ?

Ill do a quick run down of everything... some might not apply if you're buying pre-built

for a new computer, going for best bang for buck you want...

Intel i5

i7 won't make any difference at all for you (or 90% of other people either)
and you get more bang for your buck with Intel than AMD right now

they're numbered i5 4570...      i5 4250...  etc.

the first digit of the number is the version of the chip, so you want to make sure the number is 4xxx
after that higher numbers are better, but there's no a massive difference between them, just go with your gut for price vs ghz
(they're all 4 core)

ram, pick 8 gig of decent name brand ram - you could get away with 4gig but 8 is better, and not much need for more than 8 unless you're more of a power user / want to run photoshop etc..

hard drive, get 2
an SSD as a main drive, 200 ish gig is fine
and then a normal HD as backup/storage, go with your gut for size, they're pretty cheap now

(SSD is a hard drive that uses memory chips instead of spinning disks, they're crazy fast, doesn't really matter which one you get, they'll all blow you away performance wise)

GFX - just go with onboard gfx, will do everything you need without breaking a sweat - sometimes called intell HDxxx gfx if you're buying pre-built

after that... other stuff doesn't really matter, just go with personal preference... try to stick with brand names for reliability

screen... look for a bargain, you can get pretty awesome screens for pretty good prices now... especially with all the new 4k etc.. screens coming out now

Title: Re: I need a new computer (or two ...)
Post by: titan on May 18, 2015, 04:44:46 PM
I would go for Intel with on board graphics, their Linux drivers are well maintained. Another MS innovation is the UEFI which makes installing anything other than MS difficult. There are ways around it and it should be switchable in the bios but worth checking. SSD are quieter and more reliable