100Mbps Ethernet Speed/Efficiency
Laurence Orchard
laurence at orchards.org.uk
Tue Apr 6 21:28:06 UTC 2004
On Tue, 2004-04-06 at 22:18, Neall wrote:
> >> I'm wondering what's the maximum sustained transfer rate
> >> that one can experience when using a 100Mbps link?
>
> I took the hard drives out of the picture. I set up RAM disks on two
> different systems, and connected them via ethernet using NFS to cross
> mount them. Then, I copied from the first system's RAM disk over
> ethernet, to the second system's RAM disk. Granted, NFS is in the
> picture, but it would be using hard drives, too.
>
> These numbers include NFS overhead (obviously):
>
> 100 Mb file:
> 100/T: 11.335 MByte/Sec (averaged over many tests).
> 1000/T: 69.9 MByte/Sec.
>
> Obviously, the 1000/T (gigabit) test would have immediately been
> bottlenecked by the drive transfer rates. The 100/T rates are near
> theoretical. Not sure where the 1000/T bottle neck is, but I used stock
> NFS parameters. I may try to transfer via socket or rpc, but just haven't
> gotten there yet. I figured most people transfer via NFS (or SAMBA)
> mounted drives, so wanted to start there.
>
> Still, ~70 MByte/sec isn't shabby over gigabit ethenet via NFS. Neall
>
>
Hi
have you considered putting the data file in a ram disk to overcome the
disk transfer overhead? assuming you have enough physical memory so you
don't hit swapping!
Laurence
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