Share
A share is a found solution at reduced difficulty: proof for the pool that your miner was actually crunching.
What a share is
Blocks are found rarely, and if a pool waited for blocks alone it could not measure anyone's contribution. So the pool hands out jobs with a lowered threshold. Solutions that clear this threshold are shares: useless to the network, indispensable for the accounting.
The threshold is picked automatically, and that mechanism is called vardiff. The pool watches how fast solutions arrive and tunes the job difficulty so the miner submits a share every few seconds. A weak asic gets a lower threshold, an S21 a higher one.
In the stats you will see accepted and rejected. Rejected are the ones that arrived too late (the pool had already switched jobs), came in twice, or fell short of the threshold. Half a percent rejected is normal. If it climbs past two or three percent, look at the network, not the miner: the cable, the switch, the latency to the pool server.
Quick reference table
| What it is | a solution to a reduced-difficulty job |
| What for | so the pool can count your contribution |
| Types in the stats | accepted, rejected, stale |
| Normal reject rate | up to half a percent |
| Who sets the threshold | the pool, automatically, via vardiff |
Why shares sometimes get lost
Every new job voids the previous one. If a share goes out right as the pool broadcasts a new job, it arrives stale. The farther the pool server, the more often this happens, so from Spain it makes sense to connect to a European endpoint.
The second common cause is an overheated asic with a dropped frequency: shares come less often and the pool-side hashrate sags. The third is overclocking past the stability line, when chips start returning wrong solutions. In our workshop that shows up right away: rejects multiply compared to the factory profile.
Example in numbers
An Antminer S21 at 200 TH/s submits several solutions per second at a typical pool threshold. Over a day that adds up to tens of thousands of shares, and the pool computes your payout from their count. The asic itself will most likely never find a single block in its entire service life.
Related terms
Where to go next on the site
Hardware
- Antminer S21 tool
- ASIC Miner knowledge base
Software
- Software firmware
Algorithms
- SHA-256 algorithms
Questions and answers
How many rejected shares is normal
Up to half a percent. One or two percent is tolerable but worth a network check. Above three percent means a concrete problem: a distant pool, a bad cable, or an overclock pushed too hard.
Do rejected shares get paid
No. The pool counts accepted ones only. So an extra percent of rejects is money lost outright, while the asic keeps running and heating as usual.
Why is my share difficulty lower than my neighbor's
The pool sets the threshold to match your hashrate. A weaker asic gets easier jobs so solutions flow at a steady rate. It has no effect on the payout.
What is a stale share
An outdated share: it arrived after the pool had switched jobs. Usually the latency to the server is to blame, less often a flaky network inside the building.
How the terms connect
Every link in the chain is clickable. Orange marks where you are now.
Looking for an ASIC miner
The catalog holds 212 models. You can compare them by hashrate and by joules per terahash, then plug your own rate into the calculator and see what stays in your pocket.
Page written and checked by Denys Klimchuk. Updated .