Stratum

Stratum is the common language between a mining machine and a pool. Introduced in the early 2010s, it replaced the first protocols, which were too slow and too chatty. Thanks to Stratum, a pool can manage hundreds of thousands of machines by sending them lightweight jobs and collecting their results continuously.

The way it works is simple. The machine opens a permanent connection to the pool's server. The pool sends it a job: the elements of the block to build and the share difficulty. The machine varies the nonce, computes hashes and sends back every share that reaches this difficulty. As soon as a new block appears on the network, the pool sends out a new job. A more recent version, Stratum V2, encrypts the traffic and makes the messages lighter.

In the miner's web interface, a pool address looks like "stratum+tcp://server-name:port". It is paired with a worker name, often in the form account.machine, and a password, often just "x". Machines usually accept three pools, the second and third acting as backups if the first stops responding. A high rate of rejected shares often points to a server that is too far away or an unstable connection.

Our tutorials show where to enter these settings in the machines' interface.