100Mbps Ethernet Speed/Efficiency

[Neall]

On Tue, 6 Apr 2004 at 3:38pm, Joel Jaeggli <joelja at darkwing.uoregon.edu>...:

> You can build a pretty wicked disk subsystem these days. single 15k rpm
> disk-drives can read a rate of around 86-78MB/s depending on what part of

Technology Marches on!  My keeping up with it doesn't :)

> Do the machines in question have the ethernet in 64 bit pci slots?

It's an SBC, and ethernet is on board.  The schematic shows an
interconnect via 64-bit PCI-X, 133 MHz, via an Intel 82870P2 PCI/PCI-X
hub.  The eth chip itself is an Intel 82546EB.  Dual Gigabit.  Soldered
in.  Copper trace PCI, but no plug-in connectors.

> block reads on 4GB files from a netap-940 we were testing were order of
> 83MB/s using jumbo 9k ethernet frames... dropping that to 1500mtu made it

Off topic (SORRY):  Where do I tune these parameters in my NFS setup?
I'm actually running RHEL WS3.0 (not Fedora) but should be similar.

> desktop which just has 100baset. For small switched environments where
> performance is important unmanged gig copper switches now cost order of
> $20 a port or less, so if you need the speed it may be cheap.

Exactly, our plan is it run multiple SBCs but not have them communicate
over a backplane.  Instead, using an unmanaged, copper giga switch and
Cat5E between them. :)  Endpoints will be NFS-mounted RAM disks.  You
folks are demonstrating to me that it's a pretty efficient pipeline.

Neall