  Performance differences? 
 The Question is:
 
System1: Production, OpenVMS 6.2, Alpha 2100 Model A500MP, 2 CPUs, 768 MB
Memory, RAID5 w/ parity - not mirrored
System2: Development, OpenVMS 6.2, Alpha 2100 Model 5/250, 1 CPU,  512 MB
Memory, Not RAID - normal disk
 
Our customer runs our application on both of these machines (Saturday night
in batch with priority 4) but it finishes much faster on System2 than
System1 (4 minutes vs. 14 hours)
 
System1 (Production):
Charged CPU time: 01:25:26.81
Elapsed time: 14:42:35.11
Direct I/O count: 8175366
Page faults: 1260
Peak page file size: 57616
Buffered I/O count: 10712
 
System2 (Development):
Charged CPU time: 00:04:06.94
Elapsed time: 00:06:16.91
Direct I/O count: 14677
Page faults: 1197
Peak page file size: 79504
Buffered I/O count: 11141
 
A Wizard could possibly explain this!  Any ideas?
The faster I can get an answer to the customer the better our customer
support would look!
 
Thank you very kindly,
 
Barry Ramin
 
 
 The Answer is:
 
  This could be anything from fragmented disks to fragmented RMS index file
  structures to working set limitations to incorrect system tuning to
  cache-related problems to incorrect process quotas to system or RMS or
  cluster locking contention, with a plethoria of other possibilities...
 
  Initially, the most likely cause would probably be far more application
  data on the production computer than that computer can deal with.
 
  It is tempting to answer this question by putting the blame on RAID-5
  versus RAID-0. However, the DIRECT-IO count of 8 million or more versus
  15 thousand suggests that the production system simply has too much work
  to do.  Whether a (writeback cache?) RAID-5 I/O is a little slower would
  be moot, in other words.
 
  As there is insufficient detail on the application, the OpenVMS Wizard
  cannot particularly assist with specific suggestions.  For example, if
  this is an Oracle application the OpenVMS Wizard would recommend hunting
  for 'full table scans'.  For an RMS indexed file application, the OpenVMS
  Wizard would search for excessive duplicate chains.  Without even an
  indication whether the application is a data entry style or a report/query
  style, there is little that can be recommended.
 
  Start with the OpenVMS performance management manual, and spend some time
  learning about the performance and where the extra time is going.
 
  Tools of interest could include DECamds (separately installed, likely
  best to install the V7.1 or V7.2 DECamds kit on V6.2), MONITOR, and
  various performance and coverage analysis tools.
 
  For consulting assistance to help resolve this quickly, please contact
  the Compaq Customer Support Center.
 
