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Other => Beginners & Help => Topic started by: theowalpott on June 19, 2011, 05:56:04 PM



Title: Using cpu + gpu to mine
Post by: theowalpott on June 19, 2011, 05:56:04 PM
Hi,

I've just set up a gpu miner using poclbm. However, when I run python poclbm.py the only device it picks up is my graphics card. I would also like to contribute my cpu to the workload too.

I notice that in the bitcoin daemon I can set generate to "true". With it false, bitcoind getinfo shows "hashespersec" of zero, but it gets a value when true. I should also mention that when poclbm is running, I am seeing a hashrate of ~22Mh/s from poclbm which seems about right for the card I'm using.. its an Nvidia GT260 (I think - don't actually trust the drivers!).

So my questions are:

Firstly, with the generate set to false, is my gpu miner via poclbm actually working - should I see a non-zero value in hashespersec?

If I set generate to true, with poclbm running, do I get any benefit from the cpu, or should I be running a seperate cpu miner via RPC?

Should poclbm be picking up my cpu as well? - its a Xeon Q9550.

Finally, would I see any benefit from using cuba rather than opencl?

Thanks for any advice :)


Title: Re: Using cpu + gpu to mine
Post by: okashira on June 19, 2011, 06:04:25 PM
Don't use the CPU. It's just so inefficiency that it costs more in electricity then you get in BTC.


Title: Re: Using cpu + gpu to mine
Post by: theowalpott on June 19, 2011, 06:07:04 PM
Electricity isn't an issue - solar power :)


Title: Re: Using cpu + gpu to mine
Post by: fascistmuffin on June 19, 2011, 06:08:28 PM
Don't use cpu and gpu mining at the same time. Your cpu will under such a load, your graphics hashrate will drop to the single digits.


Title: Re: Using cpu + gpu to mine
Post by: theowalpott on June 19, 2011, 06:10:54 PM
The strange thing is, that when I've put generate to true - my hashrate for the gpu doesn't seem affected.

I had the cpus going at around 5Mh/s and the gpu didn't change from ~22Mh/s - does this suggest something else might be wrong?


Title: Re: Using cpu + gpu to mine
Post by: okashira on June 19, 2011, 06:12:03 PM
You can do both. just leave one core available. If you have a quad core with hyperthreading then use 7 cores.


Title: Re: Using cpu + gpu to mine
Post by: tac on July 09, 2011, 08:29:08 AM
You can do both. just leave one core available. If you have a quad core with hyperthreading then use 7 cores.
Is there really a difference in mhash/s if you use 7 or 4 cores on an quad core with hyperthreading?


Title: Re: Using cpu + gpu to mine
Post by: SteveM on July 09, 2011, 10:56:52 AM
If you have spare electricity generated, wouldnt you make more money selling that back to the grid rather than using CPU mining?


Title: Re: Using cpu + gpu to mine
Post by: blackgold on July 09, 2011, 03:34:18 PM
Using the CPU is currently a pointless pursuit. Due to the amount of power from a graphics card, even the most expensive  highest performing CPU can only attain a fraction of the speed of a low end GPU. Your better of leaving the CPU to do the job of running the OS.


Title: Re: Using cpu + gpu to mine
Post by: nmat on July 09, 2011, 03:37:52 PM
The strange thing is, that when I've put generate to true - my hashrate for the gpu doesn't seem affected.

I had the cpus going at around 5Mh/s and the gpu didn't change from ~22Mh/s - does this suggest something else might be wrong?

I did this last night and the GPU also didn't seem affected. The CPU threads run in ultra low priority so that shouldn't be an issue I think....


Title: Re: Using cpu + gpu to mine
Post by: Xtremshare on July 10, 2011, 01:41:17 AM
don't mine with your cpu, it will take forever to get 0,00001 bitcoin, don't lose your time with cpu mining