How is this possible when all I have is just 5400 RPM Seagate drives?  Something don't add up here in terms of speed?

 

Parity Check on 5400RPM - Average speed: 650.8 MB/sec

 

Do you use Parity Check Tuning plugin, or otherwise Pause parity check? 

3 hours ago, trurl said:

Do you use Parity Check Tuning plugin, or otherwise Pause parity check? 

If it is installed then Parity Check Tuning plugin corrects the speed recorded in the history to a value that accurately represent the check speed (although there can be a short delay after the check finishes before this happens).   If the plugin is not installed then if a check is manually paused/resumed the speed Unraid shows will be incorrect as it does not take account of the pause and assumes that it managed to check the whole disk in the time between the last resume and completion.

I do have Parity Check Tuning plugin indeed. 

1 hour ago, johnwhicker said:

I do have Parity Check Tuning plugin indeed. 

In which case the speed that shows in the History and any notifications from the plugin will be correct.

 

The builtin Unraid code gets the speed that it displays on the Main and Dashboard tabs wrong if there were any pause/resume during a parity check.

If you rebuild/clear a disk smaller than parity speed will also be wrong, since it's calculated based on the parity size, it's an old bug.