All three systems were deployed on a 100-node cluster. Each
node has a single 2.40 GHz Intel Core 2 Duo processor running 64-
bit Red Hat Enterprise Linux 5 (kernel version 2.6.18) with 4GB
RAM and two 250GB SATA-I hard disks. According to hdparm,
the hard disks deliver 7GB/sec for cached reads and about 74MB/sec
for buffered reads. The nodes are connected with Cisco Catalyst
3750E-48TD switches. This switch has gigabit Ethernet ports for
each node and an internal switching fabric of 128Gbps [6]. There
are 50 nodes per switch. The switches are linked together via Cisco
StackWise Plus, which creates a 64Gbps ring between the switches.
Traffic between two nodes on the same switch is entirely local to the
switch and does not impact traffic on the ring.