Re: Ranting about JVM's default memory limits...
Mark Space wrote:
Arne Vajh?j wrote:
No.
Xmx is virtual memory not RAM.
Virtual memory in general tracks physical RAM (2 to 4 times physical RAM
is a good rule of thumb),
No.
Virtual memory on all 32 bit systems is 4 GB (on Windows 32 bit
without /3GB only 2 GB is available for apps).
You are thinking about the MS usage of the term "virtual memory" - for
reasons unknown to me they use it about page file.
Xmx and RAM has very little to do with each other.
You can use -Xmx1600m on a system with 256 MB of RAM. I may
run a bit slow if you actually use that much mem though !
> but it doesn't matter. Increase virtual
memory on a system, you still have to manually change it on each Java app.
Xmx is only related to the 32/64 bitness of the OS not to amount of
RAM or size of pagefile.
With the two exceptions that too little RAM makes the program slow
and systems that run out of page file crashes.
If you upgrade from 1 GB RAM + 2 GB page file to
2 GB RAM + 4 GB page file then you do not need
to change your Xmx - you can use and you can not
get higher than approx. -Xmx1700m on both
configs.
I belive that it already does. From Xms up to Xmx.
I need the JVM to supply Xmx=available system memory for me. That's the
point.
That is a valid wish. You can always send it to SUN.
Arne