In cryptocurrency mining, efficiency is crucial to maximizing profitability. One key factor affecting mining efficiency is the occurrence of stale shares. A stale share is a valid share that is submitted too late to be included in the current block, resulting in lost potential rewards.

A stale share occurs when you submit a result (share) to the mining pool, but it arrives "late." While the share is still valid, it's too late for the current block height. Two main factors contribute to the delay in a share. The first and most obvious is the network latency between your miner and the mining pool. The lower the latency, the better, as lower latency results in fewer stale shares. The second factor is the internal latency within the miner. This includes the time the GPU takes to detect new tasks from the pool, the time for the host system to read the results once the GPU identifies a share, and potentially the time for the CPU to verify the candidate before sending it to the pool. This internal latency usually adds around 30-50 ms. Generally, if the stale share rate is below 2%, it's considered acceptable. For example, if the total latency—combining the time to receive work from the pool, the internal miner delay, and the time to send the share back—is 125ms, this typically results in a stale share rate of about 1%. Assuming a block time of 12.5 seconds (as was normal with Ethereum), that’s a total of 12,500 ms per block. Since 1% of 12,500 ms is 125 ms, this explains why 125ms of latency results in 1% stale shares. Please note that the example above is based on an older, classic blockchain, and for some blockchains, the mechanism may work slightly differently.


Minimizing stale shares is vital for maintaining mining efficiency and maximizing potential rewards. By reducing network and internal latencies, miners can significantly lower the number of stale shares and operate within acceptable performance limits. Monitoring and maintaining latencies, ideally below 125ms, ensures that miners keep stale shares under 2%, which is widely considered acceptable.