unsufficient gigabit throughput

[Chris Eckert]

hello all

system setup:

- dell running winxp, gigabit nic installed
(auto negotiation, led indicating gigabit connection)

- mac running tiger, gigabit nic installed
(auto negotiation)

- gigabit switch
(leds indicating proper gigabit connection
on both ports)

- cat 5e twisted pair patch cables

unfortunately the constellation only reaches
a throughput of 7 mbyte/s. that's way to slow for
what it is (gigabit-to-gigabit lan link).

any ideas?

thanks
chris

 

[John Wunderlich]

hello all

system setup:

- dell running winxp, gigabit nic installed
(auto negotiation, led indicating gigabit connection)

- mac running tiger, gigabit nic installed
(auto negotiation)

- gigabit switch
(leds indicating proper gigabit connection
on both ports)

- cat 5e twisted pair patch cables

unfortunately the constellation only reaches
a throughput of 7 mbyte/s. that's way to slow for
what it is (gigabit-to-gigabit lan link).

any ideas?

thanks
chris

Don't be surprised if your network isn't the problem.

You fail to elaborate on how your transfer is occurring.
I have been able to achieve about 20-25 MByte/second if I use FTP to
transfer files, but if you're using Windows Networking to transfer
files, it slows considerably... 7 MB/s is probably about right. For
some reason, NetBT seems to have high overhead. For reasons unknown,
it also seems to make a significant difference whether you are
"pushing" or "pulling" the data.

Something to play with:
It might also help to increase your TCP Receive Window. This increases
the amount of data that can be transferred before acknowledging correct
receipt.

"Information on 'Tweaking' your TCP stack"
<http://www.dslreports.com/tweaks/RWIN>

-- John