Should add following to a FAQ or a page called 'improving log4j performance'
"I discovered that adding -Dmaven.surefire.debug="-server" to the command line for SimplePerfTest yields performance similar to OS/X and Linux. The implication is that Log4j2 is benefitting greatly from the Hotspot compiler (27 nanoseconds per iteration with the default and 2 nanoseconds per iteration with -server). This probably also explains why, when I tried to to profiling with YourKit making changes to eliminate what YourKit was finding as hot spots made absolutely no difference as HotSpot was already eliminating them. However, making the changes manually might bring the performance in -client mode closer to -server."
But talk about adding it to your server java call. Also might be mentioning - On windows server systems this happens automatically - I guess Java figured out its being called on a server class environment. but it does make a difference on a developer/ QA system