power saving computing - was Re: OT Re: ComputerGiving - CamLUG project

[Paul M]

Ferg wrote:
> Me neither.  After sending that email I got immersed into that thread.
> There's quite a lot of talk of large electricity bills and upgrading
> from a consumer level supply towards the end of it.  Ouch!
> On Oct21,2008, at 14:34, Dom Latter wrote:
> 
>> On Tuesday 21 October 2008 11:50:44 Ferg wrote:
>> Even if they've got the money to spend on the electricity I cannot say
>> I really approve of using energy so inefficiently!

I've now got a UPS at home, for my home server, and it gives me a fairly
detailed power consumption measurement (using munin and the apccd to
give stats). For my electricity tariff*, 1W year costs 92p

My home server used to be my desktop, it's an Athlon Barton XP2500+
(1.8GHz?. barton = big cache variant) with 768MB DDRAM (3 x 256).

By underclocking I can reduce power consumption by 20 to 25 watts, I
don't even notice the performance drop, but I can enjoy saving £180 per
year on electricity!

CPU consumption is probably about 40W at this speed. I did consider
switching to one of the atom motherboards, especially the dual core ones
that tranquilPC do, the power saving would be about 25W, about £23 of
energy per year, so not really work the effort until the whole
motherboard can become a lot more efficient (Intel keep quiet about the
rest of the chip being power hungry!).

Western Digital Green drives save about 5W per drive if you're lucky, I
have a mirrored pair, so I'd have to spend (say) £100 to save about £8
of energy.



* => 10.5p per kWH * 24 * 365 / 1000