This bug was originally marked as duplicate of bug 209133, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.
Build: NetBeans IDE 7.3 Beta 2 (Build 201211062253)
VM: Java HotSpot(TM) Client VM, 23.6-b04, Java(TM) SE Runtime Environment, 1.7.0_11-b21
OS: Windows 8
Maximum slowness yet reported was 5038 ms, average is 5038
Created attachment 130885 [details]
Most of the time seems to be spent in
org.netbeans.modules.editor.java.JavaCompletionProvider$JavaCompletionQuery.resolveDocumentation() 100.0 4,273 ms (100%) 4,273 ms 1
which then does a lot of calls to attribute the tree. For example 53 calls to
com.sun.tools.javac.comp.Attr.attribStat() 19.024666 812 ms (19%) 812 ms 53
This old bug may not be relevant anymore. If you can still reproduce it in 8.2 development builds please reopen this issue.
Thanks for your cooperation,
NetBeans IDE 8.2 Release Boss