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 >DISCLAIMER: This email message and any accompanying attachments may contain >confidential information. If you are not the intended recipient, do not >read, use, disseminate, distribute or copy this message or attachments. If >you have received this message in error, please notify the sender >immediately and delete this message. Any views expressed in this message >are those of the individual sender, except where the sender expressly, and >with authority, states them to be the views the University of Technology, >Sydney. Before opening any attachments, please check them for viruses and >defects. >