[Bioclusters] gigabit ethernet performance

Chris Dwan bioclusters@bioinformatics.org
Fri, 9 Jul 2004 09:10:11 -0400


More than likely, the bottleneck in your data transfer is the speed at 
which bits are read from the physical disk in your Xserve.  You can 
measure data rates off the disk in a variety of ways.  The one I prefer 
is "iostat."  12 to 13 MB/sec sounds almost exactly like a single IDE 

You can improve the speed of a data storage device by striping data 
across several drives (in a RAID set), or in a variety of other ways.

Good luck with this.  Data motion is a bottleneck for many of us.

-Chris Dwan
  The BioTeam

On Jul 9, 2004, at 5:41 AM, Chen Peng wrote:

> Hi,
> We are runing a Xserve G4 cluster with SMC gigabit switch. I found the 
> network performance is not satisfactory that file transmission speed 
> is always limited to 12MB/s to 13 MB/s.
> To copy a 800MB file from one host ( to another one 
> ( using FTP, it takes almost 70 seconds when the 
> entire network is almost idle. I have verified all NIC and ports on 
> the switch, all of them appear to be "1000base TX". And the disk IO 
> speed is guaranteed to be over 40MB/s.
> We expect the average speed in gigabit ethernet should be around 
> 30MB/s. Does any one know what might be the problem?
> Thank you.
> --
> Chen Peng
> <chenpeng@alumni.nus.edu.sg>