Way back in 2004 I posted in this thread

http://www.worldcommunitygrid.org/forums/wcg/..._thread,788_offset,0#3345

I said at the time "Remember its cheaper to build 10 Athlon 2500+ PC's than 1 Athlon 64 4000+ machine"

Well time has moved on and now everyone would like to be just that bit greener and reduce their electricity bills and despite my views re: Climate Change, there's nothing wrong with trying to do more with less - efficiency being the name of the game today.

With this in mind I have built my latest WCG WU Cruncher with the hope of setting a benchmark that I know you will love to beat

only one clause - Hyperthreading does not two cores make - just one with 2 workloads of 50%

So that said here's my latest build.......

It is based around the Phenom II 905e Quad Core processor which runs at stock speed of 2.5Ghz per core and has a TDP of 65W for all 4 cores. Compare this to the 89W TDP of my 2.2Ghz Single Core Barton Socket A of times gone by!

I have it sitting in a ASUS M4A79XTD EVO motherboard which has some very pretty passive heatsinks, nice power management and plenty of tweaking opportunities http://xtreview.com/addcomment-id-9565-view-Asus-M4A79XTD-EVO.html

But how to get the power to that M4A79XTD EVO in the most efficient manner possible.... I had a look on the 80plus.org site, an organisation that certifies PSU's for efficiency, and based on cost, availability and efficiency rating I plumped for the Corsair HX750W which is Gold rated on the site here http://80plus.org/manu/psu/psu_detail.aspx?id=25&type=2 but Corsair have played safe and claim it to be Silver, but nevertheless it is very efficient and it's unlikely I will ever need another PSU having bought this monster.

It's 90.02% efficient which basically means that if your PC takes 100W at the plug 90.02W of it gets to your motherboard to power the components, the rest is blown very gently out of the PSU as heat.

So far so good..Where else can I get power savings?

I finally took the SSD leap. All that disk spinning and wafting about of the magnetic pickups costs watts so the OS (Win7) and WCG live on a very nice 80Gb Intel X25-M http://www.intel.com/design/flash/nand/mainstream/index.htm
Just 150mw active 75mw standby !!

I have 4Gb of Kingston DDR3 RAM which operates at 1.5V and I have it running at 6-6-6-20

As I am not much of a gamer I hunted around for a passively cooled graphics card and I turned up a Geforce 9500 GT, which for me is a big step up as my last graphics card was a 4200Ti (yep AGP!)

Finally I was hoping I might passively cool that 905e. With that in mind I added to my shopping list this lump of ironwork http://www.scythe-eu.com/en/products/cpu-cooler/mugen-2-rev-b.html it's a Scythe Mugen 2 Rev.B

Despite keeping my fingers crossed and it running for a fair while without it's fan the temperature kept going north. So I have had to admit defeat here, despite the arctic silver 5, and attach the fan which keeps the whole system stable by turning at just 400rpm

I have had this build running now for over a month and I have overclocked it, underclocked it, undervolted and overvolted it and lost many a work unit in this endeavour for efficiency (Sorry Kevin )

Try as I might though I cannot get it to run stable without it taking 99W/h at the socket !!!!!!!!!!!!!!!!!!!!



For my 99W I get 2636 Floating Point MIPS per core in the 6.2.28 WCG BOINC CPU benchmark

Each core is running slightly overclocked at 2.5875Ghz. 1.1V Core 1.1V North Bridge 1.2V South Bridge

All of which works out at 106.5 Floating Point MIPS/W for the main system

4 days a day of crunch time for 2.376KWh per day

Result or should I say Results

Can you do more with less? That's the green challenge

Dave

p.s. I continued the green theme with my "planet destroying" wide screen monitor It's the Samsung XL2370. All up inc optical drive, 2 1Tb WD Caviar Green drives, webcam and sound 137W/h Probably a lot less than my old CRT Monitor alone - progress