What is JVM -server parameter?

Question

I saw Java -server in http://shootout.alioth.debian.org/ for programming language benchmark. I know that -server is a parameter for running JVM. I want to know:

When

Answer 1

The -server flag will indicate to the launcher that the hw is a server class machine which for java 6 means at least 2 cores and at least 2 GB physical memory (ie most machines these days). On server class machines the deafult selection is

• The throughput gc.
• initial heap size of 1/64th of phys mem up to 1 GB
• maximum heap size of 1/4th of phys mem up to max of 1 GB.
• The server run time compiler.

Note that on 32 bit windows there is no server vm so the client vm is the default. On the other 32 bit machines the server vm is chosen if the hw is server class, otherwise it's client. On 64 bit machines there is no client vm so the server vm is the default.

A link to the hot spot faq: HotSpot