Network difficulty adjusted upward again this week, pushing revenue per terahash to its lowest sustained level in several years.
At prevailing tariffs, machines from two hardware generations ago now run at or below cash cost unless the operator has power below roughly three cents per kilowatt hour.
Public operators have responded by accelerating fleet upgrades and, in two cases, by selling older machines into secondary markets where prices have softened noticeably.
Hosting providers report rising vacancy as smaller customers hand back racks rather than pay to run unprofitable hardware.
The pressure eases only through a price rise, a fee-revenue surge or a difficulty fall, and none of the three looks imminent from current data.
