Default Values ​​for Xmx, Xms, MaxPermSize for Non-Server Machines

Question

What are the default values ​​for the following options in Java 6 on a machine other than the server?

• -Xmx
• -XX: MaxPermSize

Oracle documentation claims that:

On server class machines running the server VM, the garbage collector (GC) has changed from the previous sequential collector (-XX: + UseSerialGC) to the parallel collector (-XX: + UseParallelGC).

and

On server class machines running either a virtual machine (client or server) with a parallel garbage collector (-XX: + UseParallelGC), the size of the initial heap and the maximum heap size have changed

The page does not describe the default values ​​for non-server machines, only that, for example, the initial heap size is a "reasonable minimum". Looking at the "man page" for the java command, the following is against -Xms :

The default value is selected at run time based on the system configuration.

Answer 1

Default values ​​for JDK 1.6.0_29 for Windows 7/32-bit:

 -Xmx256m -XX:MaxPermSize=64m 

The value of this option can also be printed with the following command:

 java -XX:+UnlockExperimentalVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+PrintFlagsFinal -version 2>&1 

Then find the MaxHeapSize and MaxPermSize keys and see the default values.

 uintx InitialHeapSize := 199947456 {product} uintx MaxHeapSize := 268435456 {product} uintx MaxPermSize = 67108864 {pd product} 

More details here .