Nice. Seti on star (stellar) energy.

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To overcome Heisenbergs:
"You can't always get what you want / but if you try sometimes you just might find / you get what you need." -- Rolling Stones

Those with multiple crunchers in a given area should include the cost of cooling in their estimates. In my case it makes a big difference. During summer months my total power bill with 4 crunchers running 100% 24/7 is between $350 & $400/month.

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Delta-V

I have heard some users say that they have given up using their CPU's for crunching, and exclusively use their GPUs because it is more efficient use of electricity per credit rewarded.

I haven't seen anyone in this thread mention that.

Is it true that a CPU sitting relatively idle uses less electricity than a CPU that is crunching 24/7?

I have recently switched to this methodology myself to see how it goes.

I have heard some users say that they have given up using their CPU's for crunching, and exclusively use their GPUs because it is more efficient use of electricity per credit rewarded.

I haven't seen anyone in this thread mention that.

Is it true that a CPU sitting relatively idle uses less electricity than a CPU that is crunching 24/7?

I have recently switched to this methodology myself to see how it goes.

If a project has GPU applications available for use (as SETI does), I tend to run only those GPU apps - I don't use CPUs on the same project. But there are plenty of other projects out there that can't make use of a GPU, so that's where my CPUs hang out and help.

Is it true that a CPU sitting relatively idle uses less electricity than a CPU that is crunching 24/7?

Sorry Richard this doesn`t answer the question.

Yes, of course a idle CPU uses less electricity than a fully utilized CPU.
How much depends on the type of course.

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With each crime and every kindness we birth our future.

Try using a

Try using a

Ahh......
My good friend the Killawatt.

I have recommended it's use many times on the forums when folks had questions about just how much power this and that would add or subtract from a rig's performance, and what it would cost to implement them.

I have a half a dozen of them. And they can tell me what a rig might be doing at any time.
I have an approximation of what amount of power any particular rig should be drawing at any given time, and if I see a deviation from that, I can reboot or pull cards and retool as needed.

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"Freedom is just Chaos, with better lighting." Alan Dean Foster

Try using a

Of course i did Richard.
On my FX 8150 overclocked to 4.4 GHZ the difference is approx 80 Watts per hour.

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With each crime and every kindness we birth our future.

My 2500K rig at full load pulls 315w at the power point (includes UPS and monitor) while my 3570K rig pulls 360w (includes UPS and 2 monitors).

I'll let others work out the maths though.

Cheers.

Awhile back I ran some numbers on one of my machines, an HP xw9400 w/ 2 AMD Quad Core Opteron 2389s (8 processors) at 2.90 GHz. At idle it uses 180w. With S@H running 100% on all 8 cores, that jumps to 310w, then goes up to 425w with the GT 660 at full tilt. Bringing in a GT 650 raised consumption to 475w and, finally (for now) adding a GT 640 to the mix brought it up to about 510w.

Clearly, the CPUs are less efficient than the GPUs but, what the heck, they're there and I figure I might as well use them. The 3 GPUs are going to draw on them to some extent, anyway, though I've never tried running S@H on just the GPUs with the CPU processing suspended, so I don't know what the power consumption would be in that configuration. Perhaps I'll try it sometime.

My top rig draws about 600 watts from the mains.
Because it is cooled by a refrigeration compressor cooling the CPU to some minus 30 degrees below C, there is also that headroom.

So, it probably uses around 1000w.

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"Freedom is just Chaos, with better lighting." Alan Dean Foster

Is it true that a CPU sitting relatively idle uses less electricity than a CPU that is crunching 24/7?

I use all 4 CPU cores on both my rigs, but if I didn't that would drop my rigs' RAC's by approximately 10K per day, in my books is worth the cost of using the CPU's IMO (older and less efficient CPU's would be another story).

Cheers.

On my FX 8150 overclocked to 4.4 GHZ the difference is approx 80 Watts per hour.

Watts per hour? (W/h) ;)
Will you rephrase that? (there is no such unit)

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- ALF - "Find out what you don't do well ..... then don't do it!" :)
 

On my FX 8150 overclocked to 4.4 GHZ the difference is approx 80 Watts per hour.

Watts per hour? (W/h) ;)
Will you rephrase that? (there is no such unit)

Sounds like an acceleration to me. Watch out for meltdown...

My mistake, sorry.
It was late while i posted it.

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With each crime and every kindness we birth our future.

To pre-answer somebody's question:
During winter these additional Watts are not wasted - this energy just turns to heat and warms the room.

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- ALF - "Find out what you don't do well ..... then don't do it!" :)
 

Is it true that a CPU sitting relatively idle uses less electricity than a CPU that is crunching 24/7?

Sorry Richard this doesn`t answer the question.

Yes, of course a idle CPU uses less electricity than a fully utilized CPU.
How much depends on the type of course.

Thanks for this answer. My RAC has suffered of course but I feel this is a nice way to balance my desire to crunch and my electric bill.

Well, I was thinking about upping my RAC and after a bit of shopping, looks like I can put together a power cruncher for a little over $3,500.

Intel Core i7 4770K Quad Core
Asus SABERTOOTH Z87 motherboard
Asus Geforce GTX TITAN (room for two on the motherboard)

Should be somewhere around 718 watts of power to run it.

Morten Ross (currently #4 cruncher) has an I7/8 core on a motherboard with 3 GeForce GTX Titans and he's getting a RAC of over 33,000 on it.

Looks like he's STREAMING AstroPulse WU's every 2,000 to 5,000 seconds and getting somewhere between 250 and 900 credits per WU.

Looking at his current list of tasks, if I use an average of 4,500 seconds (75 minutes) per WU and average 550 credits per work unit and take 2/3's of that (3 vs 2 titans), I should get the following:

550 credits per 75 minutes equals 440 credits per hour times 2/3 equals about 300 credits per hour.

At 9 cents per KWH, it should cost me about 6 and a half cents per 300 credits.

On my linux box (A little over 100W continuous, dual core, no GPUs), I'm getting about 50 credits per penny of electricity.

So, not including what the 4 cores will be doing, it looks like it'll cost me *about* the same per credit.

It'll cost me the same for credits, but the credits will be coming in faster.

More power = more credits; same cost per credit, more credit = more cost.

Hmmm... I'll have to think about it a bit more and see if I can come up with a better combination CPU/Motherboard/GPU combination.

Actually that rig of Morten's has 1 Titan and a GTX690 and that RAC is rather low for that sort of setup, but that maybe due to it not have anymore work to do (all tasks have been completed and no new tasks have been acquired).

I average 38K from my 3570K with dual GTX660's.

Cheers.