Thanks for the tip. I gave it a try, but didn't note a significant 
performance difference. 

-XX:+AggressiveHeap -Xmx1400m
Run Time:527.39 -> 100.00%
Setup:54.20 -> 10.28%
Evaluate:144.12 -> 27.33%
PostEval Stats:23.50 -> 4.46%
Optimization:0.00 -> 0.00%
Breed:303.36 -> 57.52%
CheckPoint Stats:0.00 -> 0.00%

-XX:+AggressiveHeap -Xmx1400m -Xms1400m 
Run Time:529.69 -> 100.00%
Setup:57.86 -> 10.92%
Evaluate:143.68 -> 27.13%
PostEval Stats:23.64 -> 4.46%
Optimization:0.00 -> 0.00%
Breed:302.32 -> 57.07%
CheckPoint Stats:0.00 -> 0.00%


On Thu, 2 Feb 2006 10:31:19 +1100, Shane Magrath 
<[log in to unmask]> wrote:

>Why not run the VM with a fixed amount of heap memory?
>EG: -Xms1500m -Xmx1500m [-server] # fix the heap size at 1.5GB
>Advantages are:
>(a) Dynamic heap resizing is avoided thereby
>avoiding issues to do with object copies, heap fragmentation, 
generational gc etc
>(b) Garbage collection is avoided as long as possible.
>I like to run my VM heap fixed at about 75-85% of primary memory.
>I would have thought the IO costs to do with logging, perhaps check-
pointing, etc
>would have been significant, perhaps even dominant. Discounting, of 
course fitness evaluation for
>"non-trivial" problems.
>Shane Magrath
>Doctoral Researcher
>University of Technology Sydney
>PH: 61 2 9514 2527
>UTS CRICOS Provider Code:  00099F
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