Does anyone have experience/recommendations on Java heap size for the client JRE? Our IT Services guys tell me that Windows 7 handles it differently from XP, and has quite a low default. For another business app, they’ve had good results from increasing (to 512MB, which doesn’t sound that much to me), and so are considering whether to implement that for all our workstations.
Thanks in advance.
I’ve never had to change the client heap size.
Near as I can tell the last update to the primary client heap allocation functionality with Java was in 1.6.0.18:
Updated Client JVM heap configuration
In the Client JVM, the default Java heap configuration has been modified to improve the performance of today’s rich client applications. Initial and maximum heap sizes are larger and settings related to generational garbage collection are better tuned.
^ The default maximum heap size is half of the physical memory up to a physical memory size of 192 megabytes and otherwise one fourth of the physical memory up to a physical memory size of 1 gigabyte.
For example, if your machine has 128 megabytes of physical memory, then the maximum heap size is 64 megabytes, and greater than or equal to 1 gigabyte of physical memory results in a maximum heap size of 256 megabytes.
^ The maximum heap size is not actually used by the JVM unless your program creates enough objects to require it. A much smaller amount, termed the initial heap size, is allocated during JVM initialization. This amount is at least 8 megabytes and otherwise 1/64 of physical memory up to a physical memory size of 1 gigabyte.
^ The maximum amount of space allocated to the young generation is one third of the total heap size.
^ The updated heap configuration ergonomics apply to all collectors except Concurrent Mark-Sweep (CMS). CMS heap configuration ergonomics remain the same.
^ Server JVM heap configuration ergonomics are now the same as the Client, except that the default maximum heap size for 32-bit JVMs is 1 gigabyte, corresponding to a physical memory size of 4 gigabytes, and for 64-bit JVMs is 32 gigabytes, corresponding to a physical memory size of 128 gigabytes."
So it sounds like it allocates a max heap of 1/2 the available RAM on the machine, using 192MB as default and the client should auto adjust based on the applet. Applets CAN specify a heap size but Content Explorer’s applet definition does not specify, so should rely on JRE defaults.
Now I may have missed a later JRE Patch Readme in my research, but I think the above is still true.
-n
[QUOTE=drossall;21019]Does anyone have experience/recommendations on Java heap size for the client JRE? Our IT Services guys tell me that Windows 7 handles it differently from XP, and has quite a low default. For another business app, they’ve had good results from increasing (to 512MB, which doesn’t sound that much to me), and so are considering whether to implement that for all our workstations.
Thanks in advance.[/QUOTE]
Thanks. I’ve passed this back to our IT Support team for comment. As I noted, their main reason for considering changes does not relate to Percussion, but it will be easier to make the changes across all workstations and hence to affect Percussion as well.
We’re doing trials on Percussion with the new settings and some selected users. Not really expecting it to break much, but wasn’t sure whether it might speed up the editor experience.