Brains working towards machine consciousness

 On the 30th November, an email was forwarded from our 'Clean and Green' team, which pointed to a rather shocking expenditure of £3,500 on electricity on Christmas Day last year.  I assume almost nobody was working on campus, that there weren't any major displays of Christmas lights, and that most lights were not left on.  

It occurred to me to think about how much power our "Thames Blue" IBM blade center (sic) consumes, and how much of that figure might relate to that, thanks to Karsten who mentioned the subject.

Thames Blue has 2,800 cores provided on dual core blades, according a Nerc report.  Other web based sources suggest that it has 700 blades, which would imply that it is a 4-core architecture, which makes calculations a little more tricky.  Anyway, according to IBM the power consumption of such a beast is between 316 and 373 W per blade.  As we can't be sure whether these figures are completely up to date, and the exact configuration of the Thames Blue is unknown to me, I will work on a figure of 350W and assume 700 blades (obviously, if this assumption is wrong, the actual figure will be about twice the one I am going to be working out, roughly).  I will ignore air conditioning costs, and other notable outlays for the purposes of this quick calculation.

700 blades using 350W for the day is 5,880 KWh

An answer on Linkedin suggests a JS21 configuration with 224 cores consumes 18KW, which, scaled up, works out at 5,400 KWh for the day, so it appears we are in the right 'ball park'.

I assume the University has the sort of tariff which drops after the first N KWh, and that it probably pays something like 8p per KWh after the 'break'.  This would suggest, discounting the higher priced electricity as being a cost the University would have to bear anyway, that the cost of running the Thames Blue for Christmas day, ignoring air conditioning, etc. is at least £470 - and possibly twice that.

So, yes, obviously switching off unnecessary equipment is a good thing, but given this is just one system which presumably gets left on for good reason amongst many others (the various email servers, web servers etc) and although it is probably the most power hungry we have on campus, it seems likely that most of the £3,500 spent on electricity last Christmas is probably down to things other than staff leaving a PC on (especially as almost all PCs will go into standby mode).

I am not sure how many computers there are on desks throughout the University.  There are about 4,000 staff and both centrally run and local computer labs.  This probably means something of the order of 5,000 PCs on site (this figure could be wildly inaccurate).  If we assume they are all left on, and all rather inefficient, but are on standby, they might use as much as 20W each, (assuming monitors are also left on standby and are also highly inefficient).  This means they would, between them, be using 100KW, or 2,400KWh for the day; under half the consumption of the Thames Blue.  Even if they were all on, in use, they would probably only be using 5 times as much as the blade server.

According to the email "Simple measures like turning off or even unplugging unused equipment and lighting before you leave for the Christmas break will help to dramatically reduce this figure".  Whilst I definitely applaud the motive, I doubt that the assertion really holds true.