Re: iwl3945 slow for downloading

[Larry Finger <Larry.Finger@lwfinger.net>]

Felix Fietkau wrote:
> I don't know if it helps with debugging this issue, but I've seen the same
> on a laptop from a friend of mine (same card).
> 
> After some searching I found that setting the AP to g-only mode instead of
> b+g mixed made it work at decent speeds. Another symptom of this slowdown is
> that there is typically an unnaturally high number of retransmissions on the
> air, which eats up a lot of airtime.
> 
> I've spent some time looking through the code to find the reason for this
> but couldn't find anything yet (maybe somebody from Intel could help).

Just for comparison, my BCM4312 running b43 from the latest wireless-testing 
gets the following tcpperf throughput:

AP Mode          TX          RX

Mixed b/g    19.8 MB/s   23.0 MB/s
g-only       20.5 MB/s   23.1 MB/s

For these tests, the connecting end was wired to the router. The difference in 
TX speeds was about what I expected - the small difference in RX speeds was not. 
In any case, if you see a large difference with iwl3945, that would be useful 
information.

You can obtain tcpperf from http://wand.cs.waikato.ac.nz/~stj2/nsc/software.html

Larry