I’m stuck and can't figure out how to get my speeds any faster, or figure out why my transfer speed is so slow between PC’s compared to from the Internet.

Please be aware when reading this that because of how hardware reports speeds, and how software and OSes report speeds, I’m using both Bps (Bytes per second) and bps (bit per second).

  • 8bps = 1Bps
  • 8mbps = 1MBps, and so on.

Here’s my setup:

File Server:

  • OS: Lubuntu
  • RAM: 2GB
  • Wired Ethernet 100
  • Download speeds from speedtest.com is ~5MBps
  • Actual download from high seed torrent ~3-3.5MBps
  • Hard drive speed ~60MBps


  • OS: Ubuntu
  • RAM: 16GB
  • Wi-Fi B/G/N (Connected at 72.2Mbps, 9MBps)
  • Download speeds from speedtest.com is ~3MBps
  • Actual download from high seed torrent ~2-2.5MBps
  • Hard drive speed ~400MBps

Router: (Server connected via wired Ethernet, client over WiFi)

  • Wireless B/G/N with 4x 1G Ethernet ports

I’ve tried several different connections, and the best speed I’m getting according to iperf is ~1.3MBps in either direction. I've tried SMB, FTP, etc, and NFS gets me the best speeds for file transfer speeds according to the system monitor.

Actual file transfers however from client to server in either direction fluctuate anywhere between 120-200 KBps.

Both systems during transfer have 99% idle CPU time. The client is only using 700MB/16GB RAM. The server is only using 100MB/2GB RAM. HDD activity is very low compared to doing local file operations.

netstat, nfsstat, etc are not reporting any dropped packets or timeouts.

I’ve eliminated possible bottlenecks like CPU, RAM, HDD. So how can it be that I’m getting so much more speed from the Internet compared to within my LAN?


After a couple of days, and not really changing anything, I’m now all of a sudden getting over 20Mbps. The transfer speeds of 2-3MBps are much better. However, my slowest link here is the WiFi at 72.2Mbps which is 9MBps. Taking out any overhead and whatnot, I should still be able to achieve 7-8MBps but I'm not even at half of that yet.

Transfer speeds from Client to Server are about 2-3MBps. But Transfer speeds from Server to Client are about 5-6MBps.

Why are they different?

  • How are the two PC's attached to each other? If you replace all network infrastructure between the two PCs with a cross-over network cable (a straight-through will probably work if you have Gb adapters), are the transfer speeds between the PCs as expected? Jun 24, 2016 at 15:49
  • @Ƭᴇcʜιᴇ007 Via a wired and wireless router (updated question). Haven't tested directly connected to eachother but the issue is that WAN is much faster than LAN.
    – Delorean
    Jun 24, 2016 at 16:10
  • My main suspect is your router's ability to process LAN traffic, hence why I suggested eliminating it. If you haven't tried a completely different router (or a direct cross-over cable connection), then you have not ruled it out. Jun 24, 2016 at 16:32
  • @Ƭᴇcʜιᴇ007 I'll give it a shot.
    – Delorean
    Jun 24, 2016 at 16:58
  • @Ƭᴇcʜιᴇ007 So, tried to plug them into eachother, and my client laptop actually doesn't have an ethernet port at all lol. So much for that. But, now it's been a few days, I've done nothing different, and I'm getting between 2-3 MBps transfers speeds. It's better, but on my 72Mbps WiFi, that's a max of 9MBps so I should be able to get at least 7-8MBps.
    – Delorean
    Jun 25, 2016 at 17:00


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