[Beowulf] Gigabit PCI-E NIC

[Marcelino Mata]

I have searched the archive and several sites but I have not come across
an definitive answer.   We are going to build a new cluster out of
standard HP desktop hardware.   The cluster will have dual purpose as
computer cluster 80% of the time and the remaining time to be used as PC
training computers.  We have existing Linux cluster of 8 nodes (8 x
2CPU) so Linux clusters are not new to us.
 
We will run Centos 3 or 4 on them (or maybe ROCKS).  The computers we
are looking at have integrated Broadcom GB BCM5755 NIC.  This NIC will
be use for NFS or MPI traffic (to be decided based on test).  We will be
using MPICH and HP-MPI.  The main application will by ls-dyna.

As these computers will already have Broadcom NIC, should the second NIC
also be Broadcom?  From a performance/stability point of view, does it
make a difference if the second NIC is Broadcom GB PCI-E or Intel GB
NIC?  I believe Intel GB NIC is already in the kernel and is a
"favorite" amount clusters so I probably could not go wrong with Intel.
On the other hand, the system would only need to load the tg3 driver for
both cards instead of tg3 and e1000 driver.  Our existing cluster costs
of four computer with the same NIC (Intel e1000 cards) and another with
NVIDIA NIC and Broadcom NIC (nvnet and tg3).  The Intel NIC cluster has
been the most stable but I do not belive any problems on the other nodes
were NIC related.  
 
We are looking at the following NIC:
 
Intel Pro PCI-E Gigabit 82572GI Ethernet 
 
or 
 
Broadcom PCI-E Gigabit BCM5751 Ethernet 
 
The motherboard chipset is Intel 975X North Bridge/ICH7R South Bridge
with Intel Core 2 Dual CPU's


Thanks any advance,

Marcelino


The detailed spec are as follows (if it matters):

Intel
-----
Controller	 Intel 82572GI Gigabit Ethernet Controller	
Memory	 Integrated Dual 48K configurable transmit receive FIFO Buffers

Data path width	 X1, 250MB/s, Bi-directional interface
 
Broadcom
--------
Controller	 Broadcom 5755 PCI-E LAN Controller	 
Memory	 Integrated 64KB receive buffer and 8KB transmit buffer	 
Data path width	 X1	 
Data path speed 	2.5Gbit/s direction transfer rate