I built an HTPC off of an Asus P8H77-i motherboard. It has dual 60 GB SSDs in RAID1 and 4x 4TB WD Reds in R5. About 6 months ago, I was able to get 600+ MB/s writes on RAID1 and 350+ on RAID5.
However, for some reason I can't track down, now the C drive R1 reports write speeds of 30-40 MB/s and the RAID5 at 70 MB/s. I've played with cache settings in Device Manager and RST and I've tried various RST drivers from 10.x, 11.x, 12.x and 13.x branches.
I'm running Windows Server 2012 R2 on it. I've exhausted everything trying to chase this down. Both R1 and R5 write performance has fallen way down, and surprisingly the SSD R1 is even slower than HDD R5.
Any advice would be appreciated.