Fundamentals
Effective Hash Rate
Hello Miners!
Today, we will explore the meanings behind the various kinds of hash rate terms that you might interact with when you mine at Slush Pool. While at first this may seem trivial, Hash Rates ultimately determine your reward, and understanding them is essential to predict your returns.
Hash Rate
Only for the completely new users, this term might be an unknown. Hashes are the mathematical operation done by your miner, in order to find a qualifying block. This hash must be run several times, in order to meet the conditions of a valid block; this is given by the difficulty.
Hash Rate is then the number of hashes your machine can run per second. The higher the hashrate, the more powerful miner it is.
Nominal Hash Rate
As apparent from the name, Nominal Hash Rate is the number given by the hardware manufacturer, stating the theoretical output rate of the device. In practice, however, your Hash Rate will be lower than the Nominal Hash Rate.
Effective Hash Rate (EHR)
To calculate the reward, the pool uses a unique scoring system, the Scoring Hash Rate. The Scoring Hash Rate is, in turn, derived from the Effective Hash Rate. Effective rate is calculated from the hashes that are actually submitted by the miner to the pool. This means that not all of the hashes from your miner are sent, but only those which fulfill a certain criteria, such as the difficulty. These valid hashes, which are sent to the pool, are considered as “proof of work.” Wait, what is that? Well, let me explain.
Now, for that, it is important for you to understand the concept of Shares. Simply said, Shares are the valid hashes your miner sends to the pool — the number of proofs of work. But as the power of the miners varies widely among the machines used on the pool, they are assigned different jobs, in order to maximize their potential. The output will be, however, similar, as the Pool AI determines the difficulty for every miner to produce a result every 16 to 20 times per minute. As more powerful machines are computing more difficult tasks, it would be unfair to reward them with the same amount of Shares, even though they submitted the same amount of proofs of work, right?
The value of Shares is therefore modified by the difficulty assigned. If a miner submits 10 proofs of work at 10 difficulty, 100 Shares will be ascribed to him. On the other hand, in the same time, a weaker miner submits 10 proofs of work at 1 difficulty, therefore only 10 Shares will be given to him. This weaker miner will eventually reach 100 Shares, but it will take him 10 times as long, due to the weaker hashing power. (Assuming 10 proofs of work will take the same amount of time, irrespective of the hashing power, as intended by the AI.)
Still confused? Look at this table
- 1 share = 1 proof of work on difficulty 1
- 5 shares = 1 proof of work on difficulty 5 (or 5 proofs of work on difficulty 1)
- 100 shares = 10 proofs of work on difficulty 10, or 100 proofs of work on difficulty 1, or 1 proof of work on difficulty 100 (you can see the pattern)
There are other factors which will affect your Effective Hash Rate though. As for all things concerned with mining, Luck can diminish or increase your Effective Hash Rate. If you are lucky, your miner may find more valid hashes in a shorter time, thus submit them more often, which will count as Shares. But more importantly, the quality of your internet connection to the pool server will influence your miners’ efficiency. With a weak connection, hashes cannot be submitted on time, hence you receive no proof of work and therefore no shares. Unstable connections can make you lose shares too.
Tl;dr: Effective Hash Rate = Shares per second = difficulty * numbers of proof of work per second
What Next?
To assess your miner’s contribution correctly, the Pool AI derives a Score from the Effective Hash Rate, in order to calculate the Scoring Hash Rate. In short, Scoring Hash Rate is an exponential moving average of the Effective Hash Rate, taking into account the length of mining, with the last contribution counting the most. In essence, the last share submitted receives the highest score, with its value diminishing over time, as last shares are more likely to have contributed to finding a valid block. We will go in further detail in the next article on Scoring Hash Rate. If you do not want to wait, delve into the mathematics behind SHR here: Reward System.
