ReadyNAS104 Slow transfer speed from Windows PC across network.

Hi,

my 104 has been running fine for years, i swapped out the old 4 x 2TB/5400rpm disks for 4 x 4TB/5400 disks, RAID 10 as before, did a factory reset, resynced (2.5 days !!) and now transfer speeds are 11 MB/s for a large file rather than the old 50-70 MB/s across the GB network.

Same protocols enabled as before (SMB and DLNA).

I changed nothing apart from the disks.

I don't have Bitrot-protection or encryption enabled (as before), what else could cause such a dramtic loss of speed ?

Thanks if you can help 🙂