My PC (Windows 7) is connected by ethernet cable to my router (Netgear SRXN3205), which then is connected to a D-Link NASDrive (DNS 323).

Access all works fine ... but if for example I transfer files form PC to NASDrive the throughput is not as fast I expected.

Just watching 150GB of files transferring across and the average rate is only 16.5 MB/s

LAN ports on Router are indicating (LED) that speed is set to 1000Mbps.

Why are things so slow? The cable connecting the PC to the router is about 5m, and router to NASdrive 1m.

  • Are you using cat 6 cables? – Moab May 10 '12 at 20:40
  • I bet you mean transfer rate of 16.5MB/s? I edited your question, feel free to revert the changes or re-edit it. – Baarn May 10 '12 at 21:45

I try to write an answer although there is some information missing to be completely sure.

In your original question you asked about 16.5Mb/s, this means million bits per second, what I think you've seen in windows is MB/s million bytes per second. For every byte there are 8bit, so you really have 132Mbit/s here. This is still below the maximum of the logical limit but there are some additions to it.

I am not sure which protocol the NAS uses (besides FTP) but I guess for local sharing it is the SMB protocol, which is not really optimized for speed. I never really got into SMB but what I heard was, that it added a lot of additional information to the packages. (transfer info etc). This information will be substracted from your effective network speed - it has to be transfered - but will not transfer any usable data, thus windows will not count it in as data transfer speed.

  • I'd bet this is the case. The old SMB is notoriously slow, compared to SMB2.0 on Vista and up. – surfasb May 11 '12 at 5:32

Chances are either the network card in the NAS or the pc are slowing it. Not much you can do :/


could be a few things. Check cables and make sure you are connected at 1000 and full duplex (jumbo frames too). You can view that info from the web interface of the switch.

The speed better at smaller files? Say around 1gb filesize? THe hard drive(s) can have a big impact on the write/read speed and can slow transfer speeds dramatically. Transfer some large files to your Win7 computer from the nas. Is it the same speed? Open your Windows Task Manaer Network monitor, and watch the graph. Is it steady? Flat lining? Irractic?

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