My NetBeans IDE is slow. What can I do?
There are various reasons why the IDE can be slow or unresponsive. The most frequent ones will be described here with hints how to improve the performance. If you are unable to resolve the problem, ask on the nbusers mailing list or file a bug. It might be needed to provide a memory dump or a CPU profiling snapshot.
- Slow Project Scanning: See NetBeans IDE is scanning/parsing/indexing for ages?
- Problems related to memory usage If your Java process requires more memory than the underlying OS can provide, this can cause swapping of pages from/to disk. This results in significantly degraded performance.See the following topics how to address this problem: What are memory requirements of Netbeans IDE? , and How do I set the JVM's heap size?
It is sometimes useful to increase the amount of memory available to the application to allow it to manage memory more efficiently. This can reduce the time spent during garbage collection cycles.
- I/O operations slowing down the IDE
During some tasks the IDE is performing many I/O operations. Note: the ScanOnDemand plugin can sometimes help these issues. In all cases, a slow device can cause slowdown of the whole application. Typical examples are:
- Accessing resources on network drives or plugable drives like USB disks.
- Accessing resources storages using compression or encryption.
- Anti-virus applications guarding all accesses to files and scanning all executables (Tip exclude directories from scanning such as .netbeans, build).
- Drive indexing (e.g. on Windows) running in parallel.
- Notebooks running on batteries have slower I/O too.
- Many machines have a 5400RPM hard drive by standard. Upgrading this to a faster 7200RPM device can make a very big difference. New SSD disks may help a lot as well (look for the latest models that don't have the bottleneck in processing many small I/O requests).
- Problems with graphics
Sometimes the performance of painting operations can be a bottleneck (or can even cause system instability). In this case make sure to use the latest available version of the JVM and to update drivers for the graphic devices. Java2D Graphics and Imaging page contains references to documents that can help here.
Some graphic card drivers were reported to cause significant performance problems. Often the command line switch -J Dsun.java2d.d3d=false which disables DirectDraw can help.
- Performance degrading over time
This can be a result of memory leaks and it often leads to an OutOfMemoryError later. It is discussed in the What can I do if Netbeans IDE runs out of memory (OutOfMemoryError is thrown)? topic.
- Problems when running on battery power on Windows XP
This is caused by JDK BugID: [Http://bugs.sun.com/bugdatabase/view_bug.dobug_id=5095398 5095398: Graphics performance degrades unacceptably when XPS laptop unplugged (Win XP)]. The work around is to use the command line switch -J-Dsun.java2d.ddoffscreen=false, which disables the use of DirectDraw and Direct3D for offscreen images. Alternatively, you can also adjust the PowerPlay settings for the ATI chip. Users can access this through the Advanced button on the Settings tab of the Display Control Panel. Disabling PowerPlay makes unplugged performance equivalent to plugged-in performance (at the cost of higher battery power consumption, presumably).
- Problems when using the power saving features of the AMD Turion processor
Several users have reported that using the command line switch -J-Dsun.java2d.ddoffscreen=false, which disables the use of DirectDraw and Direct3D for offscreen images solved the performance problem they were seeing on Turion-based laptops. Alternatively, you can disable the power saving features of the Turion.
- Switching to a More Current JDK
- Check the release notes to determine the JDK version that is best for the NetBeans release that you are using, and switch to it.
- If you are using Mac OS X, see NetBeansMacOSX for some hints on resolving certain JDK related problems. For example if Mac OS X keeps using JDK5 by default, even after you have installed JDK6.
- Other JDK related problems
Changing your JVM's heap size can have positive effects on machines with little RAM. JDK1.5 troubleshooting guide or JDK6 troubleshooting website are good sources of information about JDK.
- Problems with Add-ons and Modules
On slower machines you can gain performance by deactivating bigger IDE modules that you rarely use. You can also go the opposite way and install the slimmer BlueJ edition of the IDE, and then reactivate modules that you need. Read more about Disabling Modules.
Generally, installing too many add-ons and unstable plugins can affect the performance of the whole IDE.
- Maximizing Windows
Restoring a previously minimized application window can take a certain time because there is a lot of I/O (partly because the application can be paged out of memory, partly because of up-to-date check that is running in such a case).
- File Browser Bug
If the IDE slows down every time you use a file browser, try to move all zip files from your desktop as a work-around.
- Slow Visual Designer (J2ME)
If your Netbeans uses Orthogonal Router to draw the connections between the forms, this looks very nice, but slows done the IDE when you have several components. You can recompile Netbeans and change the router inside FlowScene.java / mobility pack. But be aware, recompiling probably is not a task of some minutes. For Netbeans 6.9.1 you just can download and replace the module: org-netbeans-modules-vmd-flow.jar
Applies to: All NetBeans versions
See also: Release Notes