One spec decides whether a miner is worth owning. It isn't hashrate.Every terahash of Bitcoin hashrate earns the same. What separates two SHA-256 machines is the watts they burn to produce it. That ratio is J/TH.
Why it agesDifficulty trends up, so the same terahash mines fewer coins over time. The watts don't move. The lower your J/TH, the longer that math works.
Your own numberMy Farm shows your share's hashrate and watts, not the whole machine's. Divide. A 3/100 S21 XP reads 8.1 TH/s at 109 W — 13.5 J/TH.
The trade-offCheap terahash usually means high J/TH. Our shelf runs from S21 at 17.5 to S23 Hydro at 9.5, the first production miner under 10. Neither is wrong. Just know which one you're taking.
→ Every card in the shop prints its efficiency — J/TH for Bitcoin machines, other units for altcoin rigs. Compare like with like.
