66 votes
Accepted

What is nonce in Ethereum? How does it prevent double spending?

What is nonce in Ethereum? If you refer to the Glossary at Github Wiki, there are two types of nonce used in Ethereum. Account nonce - It's simply the transaction count of an account Account nonce: ...
Achala Dissanayake's user avatar
59 votes

For pool mining, what exactly is a share?

Lots of answers here, but none of them has actually answered the question "what is a share?" In almost all mining pools, a share is a block "solution" not quite good enough to be published as an ...
Jeff Coleman's user avatar
  • 22.1k
53 votes
Accepted

Is CPU mining even worth the Ether?

Some numbers - running ethminer on my CPU gives me a hashrate of 0.248 megahashes per second (MH/s). For comparison, each of my over-clocked AMD R9 390X GPUs gives me a hashrate of about 31.58 MH/s. ...
BokkyPooBah's user avatar
  • 40.3k
36 votes
Accepted

How to make miner to mine only when there are Pending Transactions?

You can load this script to your geth console Mine only when there are transactions! var mining_threads = 1 function checkWork() { if (eth.getBlock("pending").transactions.length > 0)...
niksmac's user avatar
  • 9,673
33 votes
Accepted

Geth node starts to sync from the beginning after fast sync

Why Does Fast Sync Restart As stated in Péter Szilágyi's comment above, you will have to wait for --fast syncing to complete, otherwise you will have to restart the process again. The message you ...
BokkyPooBah's user avatar
  • 40.3k
33 votes
Accepted

How to reduce the chances of your Ethereum wallet getting hacked?

(Please edit me. I'm a community wiki) Summary Don't allow TCP request on port 8545 from the Internet to be forwarded to your geth machine Don't enable --rpc without checking that only your GPU ...
31 votes

What's the best hardware for Mining Ether?

What's the best hardware for mining ethers? GPU For the highest hashrate per GPU, the answer is the AMD HD 7990 (minimum hashrate 43 MH/s), followed by the AMD R9 Fury X (minimum hashrate 28 MH/s). ...
BokkyPooBah's user avatar
  • 40.3k
27 votes
Accepted

How do Ethereum mining nodes maintain a time consistent with the network?

Ethereum nodes (regardless of mining) need to have an accurate time, otherwise they will not be able to connect to peers and to the network (https://github.com/ethereum/go-ethereum/wiki/Connecting-to-...
eth's user avatar
  • 85.8k
23 votes

What's the advantage of EthOS over Ubuntu or Windows mining?

EthOS is based on Ubuntu Linux source code which is under the GPL 3 licensing. Therefore, by not supplying the source code to ALL for free they are in violation of the licensing. I will be filing a ...
EthOS - Stolen source code's user avatar
22 votes
Accepted

Is Ethereum ASIC resistant?

According to the Ethereum white paper: The current intent at Ethereum is to use a mining algorithm where miners are required to fetch random data from the state, compute some randomly selected ...
Mike Shultz's user avatar
  • 1,212
21 votes
Accepted

How is the Mining Difficulty calculated on Ethereum?

From https://github.com/ethereum/EIPs/blob/master/EIPS/eip-2.md: Mining difficulty is calculated from the time difference between blocks. The exact formula will change in Homestead. The symbol // in ...
MrChico's user avatar
  • 1,786
21 votes

How do I decrease the difficulty on a private testnet?

You can make the difficulty static by modifying the CalcDifficulty in Geth to return a static number. Example: func CalcDifficulty(config *ChainConfig, time, parentTime uint64, parentNumber, ...
eth's user avatar
  • 85.8k
20 votes
Accepted

How does the Ethereum Homestead difficulty adjustment algorithm work?

Summary If the timestamp difference (block_timestamp - parent_timestamp) is: < 10 seconds, the difficulty is adjusted upwards by parent_diff // 2048 * 1 10 to 19 seconds, the difficulty is left ...
BokkyPooBah's user avatar
  • 40.3k
20 votes
Accepted

Why does ethereum creates a new block,without even a single transaction?

A benefit of a blockchain is that it is append-only with, in practice, immutable past blocks. These past blocks are immutable because it is very difficult (via proof-of-work) to create a competing ...
Xavier Leprêtre B9lab's user avatar
19 votes
Accepted

What is the order and concurrency behavior of multiple calls to a contract in a single transaction?

Transactions are executed purely sequentially, in an order set arbitrarily by the miner who wins each block. Higher gas priced transactions are more likely to make it into a block, so that contributes ...
Tjaden Hess's user avatar
  • 37.1k
19 votes
Accepted

Where does the consumed ether/gas go?

Gas is paid for out of the sender's ether balance, at the rate specified by the chosen gas cost. Any unused gas is refunded, and consumed gas is credited to the miner who mined the transaction, again ...
Nick Johnson's user avatar
  • 8,154
19 votes
Accepted

How to enable and mine Testnet (Morden)?

(Hi @phuong, please reply on your progress by adding comments below). Lets go through the steps to get your environment working. We will use the command line geth so we can trace through the issues. ...
BokkyPooBah's user avatar
  • 40.3k
19 votes

How do miners profit post-PoS, if at all, how will new miners get their start, and who will execute the EVM byte code (and why)?

Miners will receive transaction fees, along with (potentially) a small block subsidy. GPUs will no longer be useful, and CPU/RAM will be useful in that stakers will need to have close to perfect ...
Tjaden Hess's user avatar
  • 37.1k
19 votes
Accepted

Why do we need both nonce and mixhash values in a block?

mixhash is actually calculated from nonce as intermediate value when validating PoW with Hashimoto algorithm. But this calculation is still pretty heavy and a node might be DDoSed by blocks with ...
Anton Nashatyrev's user avatar
18 votes
Accepted

What is the default ordering of transactions during mining?

Edit: 23 June 2017 - Added Parity details (see below) Geth For the vanilla Geth implementation, the commitNewWork() function in worker.go orders in the following way: //approach 2 transactions := ...
Richard Horrocks's user avatar
18 votes

How to get ether on public testnet?

The 2 best ways I found were: 1) Instant: an ether faucet here: http://faucet.ropsten.be:3001/ 2) An hour or two: Switch on Mining from the menu Develop > Start Mining (Testnet only) or Command ...
Benc93's user avatar
  • 393
17 votes

What's the advantage of EthOS over Ubuntu or Windows mining?

From their webpage, I put the features in code format, and in italic my 2 cents on it. On a side note I'm somewhat surprised we can have opinion based posts / question in here but hey... Remote ...
euri10's user avatar
  • 4,640
16 votes

What is the total supply of Ether?

From StephanTaul on the Ethereum Forums on September, 2014: There is no maximum. 60,102,216 ethers were created during the sale, plus 2x pools of 9.9% each. 26% of 60,102,216 will be created through ...
tayvano's user avatar
  • 16k
16 votes
Accepted

How do I create my own mining-pool?

Just use geth if you don't want to join a pool. This is called "solo mining". It's done this way: One master server is running geth: geth --rpc --rpcaddr "IP ADDRESS" --rpcport PORT Other ...
Max Malysh's user avatar
16 votes

How to get ether on public testnet?

you can get ethers on the testnet simply by using Metamask plugin. here's how: You need beforehand install metamask plugin from here, then follow the steps shown in the following picture : 1-press ...
Badr Bellaj's user avatar
  • 18.8k
16 votes
Accepted

How to make Ethereum mining difficulty static for a private chain?

Modify the CalcDifficulty in Geth to return a static number, then rebuild Geth. Example: func CalcDifficulty(config *ChainConfig, time, parentTime uint64, parentNumber, parentDiff *big.Int) *big.Int ...
eth's user avatar
  • 85.8k
15 votes

CPU mining JSON_PARSE_ERROR

In reference to this: http://ethpool.org/ "If you receive frequent "JSON-RPC Problem" errors try to increase your --farm-recheck value. You should find a valid share every 1-2 minutes. If it ...
jdsika's user avatar
  • 341
15 votes
Accepted

Why not mine my own transactions?

Why shouldn't I set up a miner account, which would mine only transactions with the lowest gas-price possible - 1 wei? Yep, you can, but... Should some other miner catch them first (for some odd ...
Richard Horrocks's user avatar
14 votes
Accepted

How to mine Ether on GNU + Linux?

I wrote how to do GPU mining for Ethereum with Debian/Ubuntu here: https://www.meebey.net/posts/ethereum_gpu_mining_on_linux_howto/ TL;DR Install/use Debian 8 or Ubuntu 16.0.4 then execute: sudo ...
meebey's user avatar
  • 176
14 votes
Accepted

How fast should be an internet connection to mine ETH?

How fast should be an internet connection to mine ETH? I'm currently on a ~ 10 Mbits/s download and 1 Mbits/s upload line and it is fast enough to mine the Ethereum blockchain while performing my ...
BokkyPooBah's user avatar
  • 40.3k

Only top scored, non community-wiki answers of a minimum length are eligible