description: Introduction to proof-of-work mining with Geth
---
{% include note.html content=" Proof-of-work mining is no longer used to secure Ethereum Mainnet. The information below is included because the Ethash code is still part of Geth and it could be used to create a private proof-of-work network or testnet." %}
{% include note.html content=" Proof-of-work mining is **no longer used to secure Ethereum Mainnet**. The information below is included because the Ethash code is still part of Geth and it could be used to create a private proof-of-work network or testnet." %}
Blockchains grow when individual nodes create valid blocks and distribute them to their peers who check the blocks and add them to their own local databases.
Nodes that add blocks are rewarded with ether payouts. On Ethereum Mainnet, the proof-of-stake consensus engine randomly selects a node to produce each block.
Blockchains grow when nodes add blocks and distribute them to their peers. Nodes that add blocks are rewarded with ether payouts. On Ethereum Mainnet, the proof-of-stake consensus engine randomyl selects a node to produce each block. Under proof-of-work, however, block producers are selected by competition. The node that computes a certain value that can only be found using repeated random guesses wins the right to propose the next block. Only if a node can demonstrate that they have calculated this value, and therefore expended energy, will their block be accepted by other nodes. This secures the network. This process of creating blocks and securing them using proof-of-work is known as "mining".
Ethereum wasn't always secured this way. Originally, a proof-of-work based consensus mechanism was used instead. Under proof-of-work, block producers are not selected randomly in each slot. Instead they compete for the right to add a block. The node that is fastest to compute a certain value that can only be found using brute force calculations is the one that gets to add a block. Only if a node can demonstrate that they have calculated this value, and therefore expended energy, will their block be accepted by other nodes. This process of creating blocks and securing them using proof-of-work is known as "mining".
Much more information about mining, including details about the specific algorithm ("Ethash") used by Ethereum nodes is available on [ethereum.org](https://ethereum.org/en/developers/docs/consensus-mechanisms/pow/mining).
Much more information about mining, including details about the specific algorithm ("Ethash") used by Ethereum nodes is available on [ethereum.org](http://ethereum.org).
## CPU vs GPU
Participating in Ethereum's PoW mining requires running an algorithm called ["Ethash"](https://ethereum.org/en/developers/docs/consensus-mechanisms/pow/mining-algorithms/ethash). Geth includes a CPU miner which runs Ethash within the Geth process. This might be useful for mining on testnets or private networks where competition for producing new blocks is small. When minign was used to secure Ethereum Mainnet, CPU mining was not viable because CPU miners were easily outcompeted by more efficient GPU miners. To mine using GPUs an additional piece of third-party software is required. The recommended GPU mining software is [Ethminer](https://github.com/ethereum-mining/ethminer).
Ethereum mining used an algorithm called ["Ethash"](https://ethereum.org/en/developers/docs/consensus-mechanisms/pow/mining-algorithms/ethash). Geth includes a CPU miner which runs Ethash within the Geth process. Everything required to mine on a CPU is bundled with Geth. However, to mine using GPUs an additional piece of third-party software is required. The most commonly used GPU mining software is [Ethminer](https://github.com/ethereum-mining/ethminer).
Regardless of the mining method, the blockchain must be fully synced before mining is started, otherwise the miner will build on an outdated side chain,meaning block rewards will not be recognized by the main network.
Regardless of the mining method, the blockchain must be fully synced before mining is started, otherwise the miner will build on an outdated side chain, meaning block rewards will not be recognized by the main network.
## GPU Mining
@ -23,15 +26,16 @@ The Ethminer software can be installed from a downloaded binary or built from so
### Using Ethminer with Geth
An account to receive block rewards must first be defined. The address of the account is all that is required to start mining - the mining rewards will be credited to that address. This can be an existing address or one that is newly created by Geth. More detailed instructions on creating and importing accounts are available on the [Account Management](/content/docs/fundamentals/account-management.md) page.
The account address can be provided to `--mining.etherbase` when Geth is started. This instructs Geth to direct any block rewards to this address. Once started, Geth will sync the blockchain. If Geth has not connected to this network before, or if the data directory has been deleted, this can take several days. Also, enable HTTP traffic with the `--http` command. To reiterate, mining does **not work on Ethereum, Mainnet** since the transition to proof-of-stake.
An account to receive block rewards must first be defined. The address of the account is all that is required to start mining - the mining rewards will be credited to that address. This can be an existing address or one that is newly created by Geth. More detailed instructions on creating and importing accounts are available on the [Account Management](/docs/interface/managing-your-accounts) page.
The account address can be provided to `--mining.etherbase` when Geth is started. This instructs Geth to direct any block rewards to this address. Once started, Geth will sync the blockchain. If Geth has not connected to this network before, or if the data directory has been deleted, this can take several days. Also, enable HTTP traffic with the `--http` command.
The progress of the blockchain syncing can be monitored by attaching a JavaScript console in another terminal. More detailed information about the console can be found on the [Javascript Console](/content/docs/interacting_with_geth/JavaScript-Console.md) page. To attach and open a console:
The progress of the blockchain syncing can be monitored by attaching a JavaScript console in another terminal. More detailed information about the console can be found on the [Javascript Console](/docs/interface/javascript-console) page. To attach and open a console:
```shell
geth attach http://127.0.0.1:8545
@ -65,7 +69,7 @@ If the sync is progressing correctly the output will look similar to the followi
}
```
Once the blockchain is sync'd, mining can begin. In order to begin mining, Ethminer must be run and connected to Geth in a new terminal. OpenCL can be used for a wide range of GPUs, CUDA can be used specifically for Nvidia GPUs:
Once the blockchain is synced, mining can begin. In order to begin mining, Ethminer must be run and connected to Geth in a new terminal. OpenCL can be used for a wide range of GPUs, CUDA can be used specifically for Nvidia GPUs:
Benchmarking on platform: { "platform": "Apple", "device": "Intel(R) Xeon(R) CPU E5-1620 v2 @ 3.70GHz", "version": "OpenCL 1.2 " }
```
Note that the Geth command `miner.hashrate` only works for CPU mining - it always reports zero for GPU mining. To check the GPU mining hashrate, check the logs `ethminer` displays to its terminal. More verbose logs can be configured using `-v` and a value between 0-9.
Note that the Geth command `miner.hashrate` only works for CPU mining - it always reports zero for GPU mining. To check the GPU mining hashrate, check the logs `ethminer` displays to its terminal.
More verbose logs can be configured using `-v` and a value between 0-9. The Ethash algorithm is [memory-hard](https://crypto.stackexchange.com/questions/84002/memory-hard-vs-memory-bound-functions) and requires a large dataset to be loaded into memory. Each GPU requires 4-5 GB of RAM. The error message `Error GPU mining. GPU memory fragmentation?` indicates that there is insufficient memory available.
The Ethash algorithm is [memory-hard](https://crypto.stackexchange.com/questions/84002/memory-hard-vs-memory-bound-functions) and requires a large dataset to be loaded into memory. Each GPU requires 4-5 GB of RAM. The error message `Error GPU mining. GPU memory fragmentation?` indicates that there is insufficient memory available.
CPU mining can also be started and stopped at runtime using the [console](/docs/interface/javascript-console). The command `miner.start` takes an optional parameter for the number of miner threads.
```js
miner.start(8);
true;
miner.stop();
true;
miner.start(8)
true
miner.stop()
true
```
Note that mining for real ether only makes sense if you are in sync with the network (since you mine on top of the consensus block). Therefore the Ethereum blockchain downloader/synchroniser will delay mining until syncing is complete, and after that mining automatically starts unless you cancel your intention with `miner.stop()`.
Note that mining only makes sense if you are in sync with the network (since you mine on top of the consensus block). Therefore the blockchain downloader/synchroniser will delay mining until syncing is complete, and after that mining automatically starts unless you cancel with `miner.stop()`.
Like with GPU mining, an etherbase account must be set. This defaults to the primary account in the keystore but can be set to an alternative address using the `--miner.etherbase` command:
@ -150,26 +155,29 @@ It is also possible to check which blocks were mined by a particular miner (addr
function minedBlocks(lastn, addr) {
addrs = [];
if (!addr) {
addr = eth.coinbase;
addr = eth.coinbase
}
limit = eth.blockNumber - lastn;
limit = eth.blockNumber - lastn
for (i = eth.blockNumber; i >= limit; i--) {
if (eth.getBlock(i).miner == addr) {
addrs.push(i);
addrs.push(i)
}
}
return addrs;
return addrs
}
// scans the last 1000 blocks and returns the blocknumbers of blocks mined by your coinbase
// (more precisely blocks the mining reward for which is sent to your coinbase).
The etherbase balance will fluctuate because quite often a mined block may be re-org'd out of the canonical chain. This means that when the local Geth node includes the mined block in its own local blockchain the account balance appears higher because the block rewards are applied. When the node switches to another version of the chain due to information received from peers, that block may not be included and the block rewards are not applied.
The etherbase balance will fluctuate if a mined block is re-org'd out of the canonical chain. This means that when the local Geth node includes the mined block
in its own local blockchain the account balance appears higher because the block rewards are applied. When the node switches to another version of the chain due to information received from peers, that block may not be included and the block rewards are not applied.
The logs show locally mined blocks confirmed after 5 blocks.
## Summary
The page describes how to start Geth as a mining node. Mining can be done on CPUs - in which case Geth's built-in miner can be used - or on GPUs which requires third party software. Mining is no longer used on Ethereum Mainnet so this information is only applicable to private proof-of-work networks or testnets.
The page describes how to start Geth as a mining node. Mining can be done on CPUs - in which case Geth's built-in miner can be used - or on GPUs which requires third party software. Mining is **no longer used to secure Ethereum Mainnet**.
Joe
2 years ago