[dundee] Network bandwidth

[James Young]

Hi Paul,

Cat5e will work with gigabit although 'working with' and 'best 
performance from...' are two different things.  CAT6 moulded cables 
would be my recommendation.  Are your CAT5e's bought or made up?

What's the make/model of the switch?

Yep on the backplane - some switches are gigabit but have rubbish 
backplanes.

You could very well be getting port flapping on the switch.  5% is poor.

Best wishes,

James

Lee Hughes wrote:
> okay, for a start, use netcat to pipe stuff between your
> machines, that will rule out any winblows smb bull that
> may be effecting performance.
>
> are you...
>
> using Jumbo Frames. 9000 bytes frames are good for irq's overloads.
>
> tcp check sum offloading, some drivers are either broken,
> or you need to turn it on specifically.
>
> some gigabit network drivers don't got in to polling mode when
> there lots of interrupts being generated, that's bad, really
> really bad...NAPI is good!
>
> make sure you gigabit switch is actually capable of switching
> frames at gigabits speeds, some backplanes,switching fabrics
> are not no blocking.
>
> have a look at your cpu util when doing gigabit transfers?
> what does it look like.
>
> okay...try this
>
> setup a ram disk on two machines
> create a large file on in ram on one of the machines
>
> and netcat to the other and see what performance you get.
>
> http://datatag.web.cern.ch/datatag/howto/tcp.html
>
> http://www.enterprisenetworkingplanet.com/nethub/article.php/3485486
>
>
>
>
>
>
>
>
>
> */Paul Lancaster <paul_lancaster at blueyonder.co.uk>/* wrote:
>
>     Hi all
>
>     Ive now installed my Gigabit switch, and in three m/c's a Gigabit NIC.
>     Only down side is i'm only getting approx 6Mbit (5%)transfer rate.
>     I have managed to get 11Mbit/sec between two WinXP m/c's. after
>     manually
>     selecting 1000 Full Duplex.
>     I cant find a similar option within PCLinux
>     All transfers via SMB - SMB server running on PClinuxOS
>
>     Cards in use
>     TP-Linx TG-3269 RTL 8169 - 2 off
>     Marvel Yukon 88E8001/8003/8010 chip set integrated on m/board
>
>     TP link Gigabit Switch with Cat5E cabling
>
>     Any hints on how to improve performance, or is the best I can expect.
>
>     Paul
>
>
>
>
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