Brian's Blog

…one man's contribution to the Weeeeerly Wild World

SETI@home efforts – March to September

I last blogged about my efforts as a participant in the SETI@home project back in February when I passed the 100,000,000 credit mark. However, as the weather began warming up in March I started switching most of my computers off, and so my RAC (recent average credit) dropped from 90K to less than 3K.


Gone were the days of leaving as many computers on as possible throughout the UK summer and sweating my socks off. It was strange – when I moved into my own house I thought I would enjoy being able to leave more computers on 24/7/365 but the reality of paying my own electricity bill coupled with a greener mind, made me think otherwise after the first year.

However, now the cooler weather has been slowly returning I’ve been gradually switching things back on, and my RAC has been on its way back up throughout September.


Switching computers on after six months hasn’t been without its problems though, especially I think since one or two of them had been operating in dusty rooms that were (and still are) undergoing renovations at the time of their last use.

This one I stripped down and rebuilt, before powering it back on, since it didn’t look too healthy:


Sadly, after a week of running, my top graphics card, an Nvidia 680 decided to start misbehaving and I feared my fire-power would be significantly handicapped. I tried it in other computers and with other PSUs, but it still kept spinning its fans up to 100% when under full load, exceeding its TDP by 25% before crashing the system. Strangely though, by the time I decided, as a last-ditch-attempt, to try it with my best PSU, it was behaving itself again, and would work again in its original computer. Very strange.

Another week went by and then my poorest PSU ceased to work (a reminder not to skimp on brands where power supplies are concerned) – it stated on the label that it was capable of supplying 30A on its 12V rail, but I suspected this wasn’t true, and I only ever taxed it with my least-hungry GPU, an Nvidia 460.

Ironing out the Invalidspalit560ti

Gradually throughout the month I rebuilt each of the computers that had been ‘mothballed’ for the past six months – swapping parts here and there and cleaning things out. My top rig (seen in its dusty state above) had always produced a quantity of invalid results and I had put it down to being ‘a bit of a beast’ – having three graphics cards and two power supplies in one case that was actually two cases stitched together. But as I began separating the GPUs and PSUs into separate systems, the invalids became isolated to one particular graphics card, an Nvidia 560ti. I actually have two of these cards from Palit, but the problematic one may need ditching… or perhaps some tweaking can iron out the invalids?

Load balancing 12V rails

Since I am now one PSU and GPU down, I have put these to one side, along with a motherboard with a burnt out 12V socket. I have managed to get my 550W Antec PSU with 3 x ~20A rails to power 2 x 460s without being overloaded (it tells me when this happens by spinning its fan up to Warp 10). Having three 12V rails is awkward because two are tied to a single 6-pin plug each, and then the final rail provides sockets for me to connect 5 x molex connectors to for which I have to connect two 6-pin adapters (using up 4 x molex plugs) with the final molex plug going into the motherboard to provide extra juice for the second PCI-express slot – it’s a lot over one rail, but it copes.


Having started to crunch more regularly I’ve already seen myself re-climb the rankings in the team I’m in (GPUUG), and I’ve gone from being a 25%er to a 1%er again – the SETI@home project automatically designates these awards:


My target now is to gain a place in the UK stats, or rather, re-take the 6th place spot since ic-hep flew up the rankings and overtook all but one of us.


The person in 6th no longer participates, so once I pass them, gaining more places will depend on what RAC my computers are now all worthy of – if I can get my RAC max’d out by the end of the year then I may persuade myself to add another rig/GPU to my arsenal.


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This entry was posted on 3 October, 2015 by in Computers, SETI@home and tagged , , , , , , , .
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