[geeks] Network Slowness

[Mike Meredith]

On Thu, 24 May 2007 02:38:56 -0400, Sridhar Ayengar wrote:
> Connecting these three machines together is an 8-port HP Procurve 
> gigabit switch.  The only other thing attached to the switch is a
> Cisco 7505 router routing across the WAN connection, and its
> interface to the switch is a PA-FE-TX.  None of the machines have
> jumbo frames turned on. The Intel gigabit card in the Pentium III has
> hardware fragmentation and checksumming turned on.
> 
> The problem is no matter where I am transferring data from or to,  I 
> only get about 5.5MB/sec.  That seems kinda slow to me.  Any ideas?

That seems more than kinda slow to me ... I would expect to get better
than that with 100BaseFX.

My little list of things to try (undoubtedly you've tried some/most/all
of these) :-

* Check that each gigabit interface is *really* coming up as gigabit.
  Sometimes autodetect doesn't work and you can get really bad
  performance if that happens.

* PA-FE-TX? Is that 100BaseFX ? Might be worth disconnecting that to 
  see if that makes a difference. Some (mighty bad) switches don't like
  to do gigabit on some interfaces and 100M on others.

* Try connecting the gigabit interfaces back to back to see what
  performance you get then. 

I'd expect somewhere between 500Mbps and 890Mbps (62-112MBps),
although I'm not sure any of your machines are pokey enough to reach
890Mbps. It may just be the Procurve just isn't up to the job.

-- 
Mike Meredith (http://zonky.org/)
'I have always wished for my computer to be as easy to use as my
 telephone; my wish has come true because I can no longer figure out
how to use my telephone." --- Bjarne Stroustrup