Gigabit Ethernet Woes

[gb spam]

On 5/6/05, James Pifer <jep at obrien-pifer.com> wrote:
> I'm trying to run gigabit ethernet on a few machines that I use for
> mythtv? My gigabit switch is a DLink DGS-1005D. I have three via vt6122
> gigabit cards. One is installed in Windows XP, one is installed in FC3,
> and another is installed in an FC2 machine that I upgraded to FC3, since
> FC3 recognizes these cards.
> 
> The problem is that the performance I get, at least from scp, is worse
> than when I was connected at 100 meg. According to the link lights I am
> connected at a 1000 on both machines. When I was using the the old
> 10/100 NICs in the machine I could scp large files at around 6.0M/s. Now
> the best I've achieved is 4.5M/s.

6M/s seems a little slow for 100MB - mine used to max out at 10M. 
Under  GB I don't get much more, say 18M/s or so?  That is with scp,
and scp uses encryption which takes time.  Granted, I wouldn't expect
your speed to drop under GB, but is one of your PCs slower than the
other?

You could try something other than scp.  NFS, which is poor, gets me
25M/s, and http gets me 50M/s.

In short, you could be being held back by lack of CPU or disk speed,
not the network.