Download firmware for Bitmain Antminer S21 Immersion (301Th) from the official source. Versions: 1. Check compatibility and release details; local copies are unavailable.
Firmware is hardware-specific. Match the exact model and control-board revision, back up settings, use stable power, test one miner first, and never interrupt an upgrade. A wrong image can make the controller unbootable.
Antminer-S21Imm-AML-release-202408061155.bmu
MD5:92f7f01581c49f0d3742b2ce4029d9 91 ANTMINER S21 lmm. initial firmware. Please make sure the miner type and firmware type are the same before upgrading the miner firmware.
Sources checked 14 September 2026