I have just set up a new NAS (Buffalo Linkstation LS421DE with two 3TB WD RED drives) and the data transfer speeds are very poor. The Intel NAS performance toolkit indicates speeds between 0.1 and 3.8 MB/s and CrystalDiskMark gives 0.45 to 2.1MB/s. I managed to improve speeds marginally by increasing the frame size to 4120 and by fitting a CAT6 cable. Would I gain a significant improvement in data transfer speeds by changing my router? The Thomson is now a bit old. Are the routers currently provided by PlusNet any better? If I had to buy one would I see a significant improvement? Initially, the projected time to backup 970GB was 7 days. I plugged the cable directly into my laptop and initially this did not appear to improve matters but the transfer rate improved and the data was eventually transferred in 31 hours. I have now connected the NAS directly to the router again and transfers are slow again. Speeds seem to fluctuate, I presume that this is due to file sizes.