On Oct 26, 2006, at 9:04 AM, Smith Marc wrote:
> I have connected a wifistix-CF up to another linux machine using a
> D-LINK xtreme G access point
> The problem is the transfer speed for either a scp or rcp never
> gets about 260kB/s. That's pretty poor given that the link in
> theory gives 11MB/s on air rate.
> I would have expected scp to be slower due to encryption but the
> fact that it's the same speed as the unencrypted rcp makes me think
> the bottle neck is somewhere else.
> (using the SSH -C option to envoke compression slowed the process
> down by half again!)
> Does anyone have any ideas what could be causing the bottleneck or
> suggestions on speeding up the file transfer rate?
Recent kernel revisions have shown poor ethernet performance
(discovered recently), and it could be that poor wifi performance is
a symptom of the same problem. One report showed slow transfers to
127.0.0.1 on the gumstix.
Chris Hamlett wrote:
> Read from laptop: 6.4 MBits/sec
> Write to laptop: 5.9 MBits/sec
> Read/write over loopback interface: 35 Mbits/ec
> I read on this list that older kernels had better performance, so
> (with some difficulty) I got 2.6.11 installed and ran the netperf
> tests again:
> Read from laptop: 42.9 MBits/sec
> Write to laptop: 41.1 MBits/sec
> Read/write over loopback interface: 100.1 MBits/sec
I'm looking into this now, but there's a fair amount of ground to
cover. Bottom line is that the problem is very likely not with the
wifi performance per se, but something more generic in the network
stack, and quite likely fixable :)