Application performance puzzle

  • Thread starter Thread starter Steve Brecher
  • Start date Start date
S

Steve Brecher

I have a Java number-crunching application -- it's run by Sun's Java VM.
The Java folks didn't seem to have any specific ideas on this problem, so I
come to you.

The problem is that the run time -- same input, same output -- varies a lot,
making benchmarking of code changes (potential optimizations) difficult. On
my test case with one version of my application, the run times varied
between 120 and 180 seconds over a couple of dozen trials, with a majority
of the time clustered in the upper 120s and mid 160s. There's nothing
indeterministic or random in my Java code.

This is on my main (desktop) system. Meanwhile, a version of the same
application written in C runs in constant time (+- 0.5%). And the Java
application runs in constant time on another XP system, my laptop. So the
variation in performance is specific to my desktop + Java. My laptop has a
significantly slower CPU, so I'd like to use my desktop for performance
testing.

I've examined the list of processes and tried to remove everything that
might be a culprit. I've gazed at Task Monitor and perfmon for a while to
no effect, but I don't have much experience with the latter. No other
applications are running. Disabling the LAN connection doesn't help. I
have Norton AntiVirus 2006 installed; disabling auto-protect doesn't help.

To recap, the problem is the *variation* in application run times.

What may I have overlooked?
 
Benchmarking on a system using Norton "Anything" isn't a good
idea. Most all their home apps run multiple services and can use
20-40 Megabytes of RAM. Check your system with a program
called ProcessExplorer.
http://www.microsoft.com/technet/sysinternals/default.mspx
**On Norton installs you'll usually find a Common Client service
is the big resource "Hog". Simply disabling NAV won't halt
or stop the CCevent service from being active.
 
R. McCarty said:
Benchmarking on a system using Norton "Anything" isn't a good
idea. Most all their home apps run multiple services and can use
20-40 Megabytes of RAM. Check your system with a program
called ProcessExplorer.
http://www.microsoft.com/technet/sysinternals/default.mspx
**On Norton installs you'll usually find a Common Client service
is the big resource "Hog". Simply disabling NAV won't halt
or stop the CCevent service from being active.
Click to expand...

I'm aware of the Norton processes/services. On my laptop, where the
performance variation problem does not occur, I also have NAV, although 2004
rather than 2006. It's running CCAPP, CCEVTMGR, CCSETMGR, etc. (eight
processes in all).

The problem system has 1G RAM. My application doesn't use much. 20-40MB
isn't significant.

Again, it's the variation in performance, not absolutely slow performance,
that is puzzling me. A range of 120-180 sec. seems huge, and occurs only on
the one XP system, not the other. (Details in OP.)
 
R. McCarty

I'm aware of the Norton processes/services. On my laptop, where the
performance variation problem does not occur, I also have NAV, although
2004 rather than 2006. It's running CCAPP, CCEVTMGR, CCSETMGR, etc.
(eight processes in all).

The problem system has 1G RAM. My application doesn't use much. 20-40MB
isn't significant.

Again, it's the variation in performance, not absolutely slow performance,
that is puzzling me. A range of 120-180 sec. seems huge, and occurs only
on the one XP system, not the other. (Details in OP.)
Click to expand...

Do some clean boot troubleshooting to see what might be causing the problem.

Clean Boot Troubleshooting

How to Troubleshoot By Using the Msconfig Utility in Windows XP
http://support.microsoft.com/?id=310560

How to perform advanced clean-boot troubleshooting in Windows XP
http://support.microsoft.com/?id=316434

How to perform a clean boot in Windows XP
http://support.microsoft.com/?id=310353
 
Rock said:
Do some clean boot troubleshooting to see what might be causing the
problem.
Clean Boot Troubleshooting

How to Troubleshoot By Using the Msconfig Utility in Windows XP
http://support.microsoft.com/?id=310560

How to perform advanced clean-boot troubleshooting in Windows XP
http://support.microsoft.com/?id=316434

How to perform a clean boot in Windows XP
http://support.microsoft.com/?id=310353
Click to expand...

OK, thanks -- I'll take a look at those.

Meanwhile, update: I removed Norton NAV 2006, all components. After, test
run timings were:
94.4, 110.9, 107.7, 109.7, 94.3. Still puzzling. (Note: 120-180 range
reported previously was for a previous, slower, version.)
 
Steve Brecher said:
OK, thanks -- I'll take a look at those.

Meanwhile, update: I removed Norton NAV 2006, all components. After,
test run timings were:
94.4, 110.9, 107.7, 109.7, 94.3. Still puzzling. (Note: 120-180 range
reported previously was for a previous, slower, version.)
Click to expand...


The variation seems less but still higher. Something is jumping in there
and interfering. Hopefully clean boot troubleshooting will pinpoint it. Is
indexing service turned on?
 
Back
Top