The attached test bigobj.java (created for bug 6845368) creates a single instance of a very large object w/65000+ fields. It finishes in 1 second or less with a product build, but takes 5+ minutes with a fastdebug build on a fast machine.
JDK-2181934debug code in ciObjectFactory too slow for large objects
JDK-2182191debug code in ciObjectFactory too slow for large objects
JDK-6845368large objects cause a crash or unexpected exception