Jetstream allocations are measured in XSEDE Service Units (SUs). On Jetstream, SUs are consumed at a rate of 1 SU per vCPU-hour (use of one virtual CPU per hour). For more information on XSEDE Service Units, see the XSEDE KB document “On XSEDE, how are compute jobs charged?”
The SU cost rate per hour for each Jetstream VM size is outlined in Virtual Machine Sizes and Configurations.
Only instances that have an Active (green status light) decrement SUs.