tag:blogger.com,1999:blog-8712770457197348465.post7187794309703575187..comments2024-03-29T00:43:22.798-07:00Comments on Javarevisited: What is -XX:+UseCompressedOops in 64 bit JVM? Examplejavin paulhttp://www.blogger.com/profile/15028902221295732276noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-8712770457197348465.post-53813187222688934142016-09-21T03:14:59.323-07:002016-09-21T03:14:59.323-07:00Hi,
Thanks for your explanations.
You said : '...Hi,<br />Thanks for your explanations.<br />You said : ''Though it's important to note that use of Compressed Oops option limits your heap size up to 32Gigs which are still more than handy but yes a limitation if you looking for a seriously gigantic heap''. I have -Xmx and -Xms set to 114688m. Should I conclude the +UseCompressedOops is useless, or worse ?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8712770457197348465.post-54383943386467771262015-07-11T00:12:25.000-07:002015-07-11T00:12:25.000-07:00@Anonymous, You might be running your Java Program...@Anonymous, You might be running your Java Program in JRE version less than 1.6, since this JVM option is only introduced from Java 6, starting your JVM in Java 5 with -XX+UseCompressedOOP will fail with error "failed to start Java Virtual Machine". Please check your JVM version.javin paulhttps://www.blogger.com/profile/15028902221295732276noreply@blogger.comtag:blogger.com,1999:blog-8712770457197348465.post-70313608328231135472015-07-10T02:28:46.676-07:002015-07-10T02:28:46.676-07:00I am getting following error reated to compressed ...I am getting following error reated to compressed oops :<br />"Unknown VM option UseCompressedOOP, failed to start Java Virtual Machine". Please advise.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8712770457197348465.post-81234965604928972522014-02-03T18:59:36.808-08:002014-02-03T18:59:36.808-08:00Compress OOPS option is by default enabled form Ja...Compress OOPS option is by default enabled form Java 7 release. Since going from 32-bit to 64-bit machine increase heap requirement for Java application almost up-to 1.5 times, simply because of bigger ordinary object pointers, its important to use -XX:+UseCompressedOops in Java version prior to 1.7. Compressed Oops manages 32-bit pointers, which means similar heap sizes for 32/64-bit apps. Also Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8712770457197348465.post-42932967100867683242012-06-26T07:47:31.985-07:002012-06-26T07:47:31.985-07:00@Pavan, Thanks for your comment knowledge of JVM t...@Pavan, Thanks for your comment knowledge of JVM tuning and basic options are becoming increasing important because of development of higher performance Java application, especially in high frequency trading space. -XX:UseCompressedOoops has resulted in better performance in 64 bit JVM. by the way I see your point. keep in touch.<br /><br />JavinJavin @ ejb questions answershttp://javarevisited.blogspot.com/2012/03/top-10-ejb-interview-question-and.htmlnoreply@blogger.comtag:blogger.com,1999:blog-8712770457197348465.post-31738694225379782762012-06-25T21:27:21.098-07:002012-06-25T21:27:21.098-07:00Mr. Paul, It is nice posting for 64bit JVM users, ...Mr. Paul, It is nice posting for 64bit JVM users, Better you give more quantification and baseline functionality would be more value added.<br /><br />However, thanks for your time and very useful posting.Pavan Devarakonda [PD]https://www.blogger.com/profile/06638309611528564002noreply@blogger.com