Re: Not so good pcmcia lan performance
On Mon, 29 Sep 2003, Nicolas wrote:
> Today a guy at work ask me to test my pcmcia nic card. We transfered a big
> file via NFS. We watched the "performances" with nload. The average
> transfer speed was between 600 and 800 kBit/s. I tried to transfer the same
> file from the PC on my desk (less ram and CPU) and we got about 12000KBit/s.
>
> That's a huge difference. I have a Xircom CBEM56G-100 (10/100 + modem) and I
> use CardBus + yenta_socket on 2.6.0-test6. I can't reboot now, as I say I'm
> at work :o) Is there a way to have better performance with my card?
>
> Nicolas
Were you connected to a switch, or a hub? Did ifconfig say you were
connected at 100mbps full duplex, or at 10mbps half duplex? If it was a
hub - any other traffic could interfere - and if a switch, any traffic
headed to your destination could also interfere. It's possible that the
driver is just poor - as laptop nics don't tend to get stress tested like
stuff that goes into servers - but it seems likely that there's something
else (interrupts keeping network busy, etc.). Also - where were you
transferring to - was it just between the two? Were you reading
everything through nload, etc.... lots of factors need to be known
overall, but my first guess would be either hd bottleneck (laptop hds are
slower - insanely so if you haven't done some hdparm tweaking) and
interrupts, with the possibility of driver imperfection.
-Martin Norland
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