Java SE 6 Update 14 Release Notes. - Oracle
This update featured , which integrated several optimizations originally slated for later versions like Java 7. J2Se 6 Update 14
: Support was added for Windows Server 2008 SP2 and Windows Vista SP2 . Java SE 6 Update 14 Release Notes
Update 14 was essentially a "feature backport" release. By including G1 and compressed pointers, Sun gave developers a preview of the performance gains coming in Java 7 while maintaining the stable environment of Java 6. Update 14 was essentially a "feature backport" release
: A new optimization ( -XX:+DoEscapeAnalysis ) allowed the compiler to determine if an object is "escaped" (used outside a method). If it isn't, the JVM can allocate the object on the stack instead of the heap, significantly speeding up execution and reducing garbage collection overhead.
: The -XX:+UseCompressedOops option was introduced to improve the performance of 64-bit JREs on heaps smaller than 32GB. It allows 64-bit JVMs to use 32-bit references, reducing memory footprint and improving cache efficiency.