Slow network transfer speeds

Discussion in 'Networking & Security' started by ep3w, Apr 13, 2013.

  1. ep3w

    ep3w Gawd

    Messages:
    627
    Joined:
    Apr 4, 2008
    Here is my setup:

    2-Desktop PCs
    2-Qualcomm Atheros AR938x wireless cards, both connected on 5Ghz network at 450 Mbps
    Router-E4200, latest firmware, the only 5Ghz network in the area

    One PC has a drive bender drive pool on it that I'm trying to read/write from. Testing the pool w/ crystal disk mark on the local pc shows fast speeds (650 MB/s read, 67 MB/s write), so I drive bottlenecks aren't the issue.

    Connecting at 450 Mbps i would expect to see something like at least 200 Mbps actual speeds, or is this off? Using LAN Speed test I'm getting 41 write and 52 read. Not great. Any ideas here whats going on? Thanks!
     
  2. Liger88

    Liger88 2[H]4U

    Messages:
    2,661
    Joined:
    Feb 14, 2012
    200Mbps if you are lucky, or shall I say "theoretically". There is so much more than just the contention aspect, which is a straight 50% off any advertised speed they tell you.


    The problem isn't the PC's, Router, or the Wireless cards. They are working exactly as expected. The problem my friend is, the Wireless. Those speeds are not completely unreasonable given the circumstances. If you're going to want more you're either going to have to invest in bleeding edge 802.11ac equipment or hardwire.
     
  3. Grentz

    Grentz [H]ard as it Gets

    Messages:
    17,147
    Joined:
    May 5, 2006
    Usually you can expect around 100 MB/s - 150 MB/s on gigabit with overheads/etc. involved. Just as a reference.
     
  4. ep3w

    ep3w Gawd

    Messages:
    627
    Joined:
    Apr 4, 2008
    I knew overhead was bad, but I didn't think it would be that bad. There isn't an interference or anything and both have strong signal. Trying to stream video is nightmare over the connection. I've tried disabling any QoS on the router etc and nothing changed.

    Edit: As I was typing this I tried the test again. I'm now getting 80Mbps write and 87 read. Still not quite what I expected but I'll take it.
     
  5. Jesse B

    Jesse B [H]ard|Gawd

    Messages:
    1,631
    Joined:
    May 30, 2010
    150MB/s is over the theoretical limitation for gigabit, which is 125MB/s. Anything over 100MB/s is excellent performance, I've never seen (personally) anything more than ~110MB/s.

    As others have said, and I'm paraphrasing, wireless sucks. If you want to see what your setup is capable of, try running iperf over the wireless and see what kind of speeds you get.
     
  6. Grentz

    Grentz [H]ard as it Gets

    Messages:
    17,147
    Joined:
    May 5, 2006
    The best I have seen is 140 MB/s, but that is on a couple 100 grand worth of Cisco gear and an enterprise SAN :p
     
  7. Blue Fox

    Blue Fox [H]ardForum Junkie

    Messages:
    11,659
    Joined:
    Jun 9, 2004
    That's not possible. The IEEE standard is one billion bits per second and that would be over it. There is no way around it with a single link.
     
  8. Grentz

    Grentz [H]ard as it Gets

    Messages:
    17,147
    Joined:
    May 5, 2006
    Probably crappy windows speed meter then, it did only bounce up there a couple times.