Would it be an idea to tcpdump a 'good' and 'bad' card to confirm
	this?

-- 
		David/absolute		-- www.netbsd.org: No hype required --


On Fri, 13 Jul 2001, Jukka Marin wrote:

> On Fri, Jul 13, 2001 at 12:13:03AM -0500, Kazushi Marukawa wrote:
> > I experied slow NetBSD samba server.  Then, I bought many
> > NICs with a hope to improve the speed and failed.  At last,
> > I got good cards finally.
>
> Sounds like the samba clients are flooding packets to the server so fast
> that the server can't pick them up from the Ethernet card, so packets
> get lost and retransmission timeouts cripple the transfer rate.  The reason
> for the server dropping packets may be "CPU too slow" or "the server's
> interrupts are blocked for long periods of time".  The latter could probably
> be caused by disk I/O with a stupid disk controller..
> Of course, it could also be a bug / misfeature in the Ethernet card drivers.
>
> Some cards perform better if they are able to DMA the packets into larger
> buffers in the system RAM, if they have largers FIFOs for system bus latency
> compensation etc.
>
> I was having problems with a NE2000 compatible card on my router when using
> NFS - the card was dropping packets when a fast card was transmitting.  I
> replaced the card with a Tulip based one and the problem went away.
>
>   -jm
>
>