running on ramdisk?

Richard Christie richard at
Sat Jul 26 18:06:53 BST 2003

Hello Molpro-users,

I'm trying to run many small calculations in as short a time as possible.

For a HF calculation, I am writing all integrals to disk, rather than
using the direct implementation. However, when I try to run such a
calculation, I get the following timings:

 PROGRAMS   *        TOTAL    HF-SCF       INT
 CPU TIMES  *        10.01      3.04      6.89
 REAL TIME  *       122.40 SEC
 DISK USED  *       305.25 MB

What causes the difference in time between the CPU time and the REAL
time? An I/O bottleneck? The timing for the writing of integrals to disk

 PROGRAMS   *        TOTAL       INT
 CPU TIMES  *         6.97      6.89
 REAL TIME  *        91.87 SEC
 DISK USED  *       305.25 MB

Is there any way I can minimize the (REAL - CPU) time difference? I've
tried writing to ramdisk instead, but this doesn't improve upon anything.

Richard Christie

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