I've got an Areca ARC-8050 thunderbolt (1) raid array set up with 8 4TB WD enterprise class hard drives, in RAID 6 mode. When I first tested it I was getting over 400 or 500 MB/s in both read and write speeds. Now, write speeds are still very fast but read speeds have degraded to around 90-150MB/s. I contacted Areca support and their suggestion is to delete and recreate the array, not a very good option as I've got 18TB of data on there now. Anyone have any ideas as to why the read speed might have slowed down and what to do about it? I'm not incredibly familiar with all the settings you can change when setting up a RAID system like this; I pretty much went with the defaults the system offered. This is attached to a late 2013 iMac. I ran a disk verify through Disk Utility and it found no errors.