the article is primarily about how RAID6 will lose it's advantage over RAID5 as disk sizes get bigger, but it says a lot about the lack of resilience in RAID5 arrays on large disks, particularly non-enterprise SATA disks.
http://storagemojo.com/2010/02/27/do...rking-in-2019/
if I'd read this before I'd built my RAID array in my n7700, I'd most definitely have used RAID6 instead of RAID5 and just taken the hit on losing available space.
Now I'm dreading what's going to happen when I do lose a drive and having to take the gamble on a rebuild.