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