Xeon (2.4GHz) x 2
cpu/pe walltime
192 264 (72)
Xeon (2.4GHz) x 4
cpu/pe walltime
113 190 (77)
Pen 4 (3.0GHz) x 2
cpu/pe walltime
148 184 (36)
Timing measurments by DFT Molecular Dynamics code
(ab initio molecular dynamics code)
● 181 (C,N,H) atoms, 60x60x192 grids, 2 SCF iterations
● Red Hat Linux 7.3, Portland Fortran/C compilers 5.1,
Scalapack package (self compiled)
● Xeon 2.4 GHz - smp (dual)/533MHz FSB, chipset intel E7505
PC2100 512MBx2, Hyper-threading is off
● Pentium 4 3.0GHz/800MHz FSB, chipset intel 875P
PC3200 512MBx2
● Communications via Gigabit network
a) on board NIC, b) on board bcm5700, c) 3Com996
Oct.1, 2003/May 10, 2004
Computation with two Pentium 4 machines is faster than with a 4-Xeon (dual
cpu)
cluster, which is possibly due to the single NIC for dual cpus or memory
band-width limitation of the Xeon architecture.Performance of the Pentium
4 cluster is excellent
for the ab initio molecular dynamics code, except for the communication
overhead.
Interestingly, the computation per processor with the Pentium 4 is even
faster
than that with the Xeon cpus in terms of the processor's clock speed ratio.
Pen 4 (3.0GHz) x 4
cpu/pe walltime
79 129 (56)