ReadyNAS 4312X Initial Sync Incredibly Slow

I have created a RAID 10 array and it completed syncing within almost precisely 2 days (48 hours, 21 minutes, and 16 seconds).

The way I did it was by following the advice here. I am going to paraphrase it here in case that page ever goes down in the future.

1. Create a RAID 10 array using the ReadyNAS GUI as usual.
2. Stare, mouth agape, at how long that volume will take to finish its initial sync.
3. Enable SSH under the settings tab so you can get shell access to your NAS.
4. Log in with the user name "root" and the password whatever you gave to the "admin" user of your NAS.
5. Set the "read ahead" of your array to 32 mebibytes with the following command:
   blockdev --setra 65536 /dev/md127
   (it's 65,536 times 512 bytes which comes out to 32 mebibytes)
6. Disable NCQ on all your drives. I'd recommend you make a script for this as follows:
   #!/bin/bash
   for drive in sd{a..l}
   do
   echo 1 > /sys/block/$drive/device/queue_depth
   done
   The part that says {a..l} assumes you have 12 drives. You're going to need to change the l to whatever the last disk letter you have is.
   According to some sources, this doesn't actually disable NCQ. It would require a kernel parameter to do that but I have no idea how to set kernel parameters on ReadyNAS OS 6. The kernel parameter is:
   libata.force=noncq
   So maybe at some point the Netgear devs can implement it. The rationale is, apparently mdadm can do the queuing better than the hard drive can so you want to disable all the disks' NCQ.

One of the recommendations from that link (Tip #5) is to create a bitmap. I think that just makes resyncs or rebuilds faster but I don't believe it makes initial syncs faster so I would just ignore it.