I have just bought a new NAS (http://www.amazon.co.uk/Netgear-RND2110-ReadyNAS-Duo-1000GB/dp/B0016KVW96) and set up two drives in it in RAID1. I connected the NAS via a gigabit connection but the transfer rate won't seem to budge over 30mb/s when reading and tends to get stuck at around 15mb/s when writing.
The primary drive is a Seagate Barracuda which runs at 7200RPM, so I think that drive should be able to hit around double what I am getting at the moment; and the second drive is a Samsung EcoGreen F2 which according to these benchmarks should be performing quite well: http://www.tomshardware.com/reviews/1.5tb-hdd-caviar,2331-6.html
My question is - does a RAID1 array copy all the data to the secondary hard drive at the same time as it is being copied to the primary drive? Therefore giving a theoretical reduction in performance?
The main thing I am struggling to understand is the read speed more than anything, so if anyone can shed some light on that it would be appreciated.