Odd NAS Array Performance

[Bayonet]

So I have just set up a BTrfs RAID6 across twelve 4TB hard drives in my NAS and decided to benchmark the performance. I used CrystalDiskMark and noticed that, while the write speeds were what I was expecting, the sequential read speeds were much slower. File transfers exhibit the same behavior.
I would have thought read and write speeds on spinning drives in BTrfs RAID6 would at least be comparable, if not skewed in the favour of reads (considering the parity). Does anyone have a similar experience or is able to explain why this is not the case?

 

[Disparia]

https://btrfs.wiki.kernel.org/index.php/RAID56

The parity RAID code has multiple serious data-loss bugs in it. It should not be used for anything other than testing purposes.

Certainly odd, but with that recent recommendation I'd look into implementing redundancy by another means instead of troubleshooting.

 

[Bayonet]

https://btrfs.wiki.kernel.org/index.php/RAID56



Certainly odd, but with that recent recommendation I'd look into implementing redundancy by another means instead of troubleshooting.

Good thing I am only using it for testing purposes then, still surprising that after more than a year that issue is still not fixed. I would have thought it would be a top priority, but who am I to say.
Edit: Ah, turns out that issue, despite being present in version 3.19 onward, was only discovered last month.

 

[slozomby]

with that many drives a hardware raid controller would be good to have.