IBM (can click through to see calibration of each processor): https://quantum-computing.ibm.com/services?skip=0&systems=al...
IonQ (overall benchmark): https://www.nature.com/articles/s41467-019-13534-2
Rigetti: https://qcs.rigetti.com/qpus/
Honeywell: https://www.honeywell.com/us/en/company/quantum/quantum-comp...