It’s called TLER (Time Limited Error Recovery). Most desktop drives can and do go into error recovery and can take up to 2 minutes to do it. If that were to happen in a RAID environment, the array would time out waiting for the drive to recover and the drive would be dropped out. TLER limits the amount of time for the drive to do error recovery to 7 seconds. This prevents the drive dropping from the array.
The other difference is that WD puts the drives through more stringent development and testing for failure rates, since these kind of drives will usually be running 24/7.
