I have a Windows Server with 20 cores at 2.10 Ghz (AMD Opteron 4171 HE). I am currently using Ufasoft CPU miner and getting about 35 Mhash/s.
I want to know what is the fastest CPU miner that I can use.
The official bitcoin client from bitcoin.org has a CPU mining option. Add a file named
bitcoin.conf to the bitcoin data directory, with the contents
I know this is an old question but recently I got a similar server.
Personally the best I've found is CPUMiner. With a hash rate of about 75MH/s, it takes a bit of setting up as CPUMiner is normally used for Litecoin mining. CPUMiner gave me about 10%-20% more than the closest rival, which was rpcminer.
I've placed the following text in a .bat file that starts CPUMiner with the correct arguments.
minerd.exe -o http://[pool url]:[pool port] -u [username] -p [password] -a sha256d -R 2
The last 2 options are
-a sha256d - This tells CPUMiner to use the sha256 algorithm, used for Bitcoin mining.
-R 2 - Indicates the number of seconds to wait for when the pool cannot be found. I know this seems a little soon, but change yours to whatever you want.
The original question was [sic] "What is the fastest CPU miner that I could use". Based on the answers, it seems, that everyone by default went to cpuminer/minerd. I use it also. However...
bfgminer (all except the latest version) has the ability to be used as a cpu miner. I have not been able to optimize mine yet but I do know that it is an incredibly smart miner with many options that can be set for performance.
So, cpuminer/minerd is great for being able to download and mine with your cpu all with no extensive testing, tweaking, etc. But if you want something that you can play around with, tweak, also to have built in Stratum, etc, then you may want to also dl bfgminer and play around. Especially if you want to cpu mine other alt coins (ie BBQ, Alpha, Xen, etc---anything with a low difficulty).
And if the day comes where you are ready to mine with a gpu, bfgminer is most likely going to be one of the miners you will use.
You might be better off doing it by hand.
But mining speed varies by application. I might have the same computer here but there is a defect in one of the prongs on the cpu, it might always run .1Mhash slower than any other chip. Yours might run faster. No one can tell you how fast or how much better software might run for you.
It is a very hard question to answer, send me your server and I'll test it out for you. Or you could just download a few miners, try them out, and decide which works better for you.