Is there a simple command that will reliably test disk performance, similar to iperf3?  Looking at ways to improve array performance, and with recent replies to another thread indicating that unraid only performs as fast as the slowest disk (something I learned long ago and then forgot), I'm left with either looking up the MFG performance specs of each individual disk (20 total, huge mix and match), or just running a benchmark of sorts to see which disks I should start replacing one by one.

 

Thanks.

Use the diskspeed docker.