- Bitmain has just announced a new chip, the BM1397 chip. Claiming 30J/TH, a 28% improvement over the BM1391. (the chip in the T15 and S15). https://blog.bitmain.com/en/bitmain-announces-next-generation-7nm-asic-chip-for-sha256-mining-delivering-breakthrough-energy-efficiency/ 27 comments btc