Dual Mining with Claymore on AMD GPUs
Mining two coins at once sounds like it could be twice as profitable as mining a single coin. This is far from the truth. It can be more profitable than just mining one coin with Claymore, but this is not always the case either. The secondary coin that gets mined alongside the Ethash coin (usually Ethereum) is working at a greatly reduced rate over what could be achieved just mining that coin. The performance lost on the main coin to provide power for the second coin is not insignificant either, though this can be adjusted when mining with AMD cards. There is also the additional 1% dev fee that kicks in when using Claymore's dual mining mode, so instead of just paying a 1% dev fee, the fee is 2%. It is possible to remove the dev fee, but doing so also cuts some of the acceleration features out of the miner, and results in something closer to a 5% performance loss, rather than just the 1%-2% dev fee. Now that we've covered the main caveats, let's look at what we can accomplish with dual mining.
Secondary Alt Coins
The main coin mined by Claymore must be an Ethash coin. Ethereum, Musicoin, Expanse, Ethereum Classic and a few other alt coins should all be mineable as the main coin. The secondary coin cannot be an Ethash coin, but must use a completely different algorith. Here are the options for secondary coins and their algorithms:
- Siacoin - Blake (2b)
- Decred - Blake (14r)
- PascalLite - Pascal
- Pascal Coin - Pascal
Claymore Dual Miner
You can find the latest releases for Claymore for Windows and Linux on Nanopool's Github. It works for both Nvidia and AMD cards and is currently the fastest miner for Ethereum. I have covered Ethereum mining with both Nvidia and AMD cards in detail elsewhere, so this page will focus on dual mining with Claymore, which is mining an Ethash coin with another coin on a different algorithm. The secondary coin usually gets a very small amount of performance as most of the hashing power goes to the main coin. This is where the main difference lies between dual mining with AMD cards and with Nvidia cards. Dual mining with Nvidia cards seems to only offer a static ratio of hashing power between the main and secondary coins. AMD cards work differently with Claymore and you can adjust to at least some degree the amount of hashing power taken from the main coin operations and spent mining the second coin. This adjustment is made through a value labeled "dcri". Changing the "dcri" value can be done before the miner has been started or while it is already active. Before you start the miner, the batch file or command line entry can include a value between 1 and 30, with higher numbers throttling the secondary coin mining upward and lower numbers favoring the main coin's hashing power. Near the end of the command to start the miner, the value is entered following a space following the characters -dcri. If there is no -dcri issued when starting Claymore, it uses a default value of 30. After the miner is started, the minus key can reduce this value one step at a time to slowly transfer some hashing power away from the secondary to the main coin. The maximum dcri value starting with version 10.0 of Claymore, at least for LBRY, should be 1000, which I presume transfers a much greater deal of mining power to the secondary coin at the expense of the main coin.
Since dual-mining generates two different alt coins, you will need two different wallets to collect those coins from your pool. I discussed Ethereum Wallet coupled to Mist on the Ethereum mining pages, and here is the link to the latest release for that: Ethereum Github. Depending on which secondary coin you choose to mine, you will need a wallet for that as well. I have discussed both LBRY and Siacoin's UI wallets on other pages in this site: LBRY | Siacoin. I have not personally mined Decred, Pascal or PascalLite yet. When/if I get a chance to do some research with those, I will reveal what I find out about downloading and using those wallets as well.