How to fix crap applet frame rate on Mac

I noticed that my computer at home could run applets fine but my work computer would stutter at 1 or 2 FPS. I finally found the discrepancy.

Go to Applications/Utilities/Java Preferences

Run applets:
Within the browser process

I switched to the other option (in their own process) thinking I’d get better performance and would avoid the occasional entire browser freeze from applets, but it turns out this totally borks everything, so don’t do it.

I can now play all the Java 4k games just fine on my Mac. :slight_smile:

Well, for me (10.5) this option was selected anyway (and marked ‘default’) and I still cannot play many of the 4k games.


Is Mac running the OpenJDK or the normal Sun Java?

Because OpenJDK is crap. It was default on my Linux, and only causes problems.

That’s what i have:

$ java -version
java version “1.5.0_26”
Java™ 2 Runtime Environment, Standard Edition (build 1.5.0_26-b03-376-9M3263)
Java HotSpot™ Client VM (build 1.5.0_26-156, mixed mode, sharing)


Apple totally borked their java plugin2 (out of process) option. This is because they now render everything to an offscreen buffer before drawing it again onto the screen. They do this because they claim it allows html content to overlap the java applet. The changes massively effected performance on all java applets (especially games and cool libraries like PulpCore) and totally broke all opengl java applets (both JOGL and LWJGL).

brought the performance on (mac && 1.5 java) of my last game back to normal.

Thank you. I just put this on the Runtime Parameters options in Java Preferences … seems to have fixed all the 4k games.

Nice to hear! I spent a lot of time fiddling with the parameters. Finally I gave up because you can’t force a normal Mac user to manually change Java settings. (It does not work in Applet tags!). Never touched a Mac since:)

Ah yes, that too. I forgot to mention it.

Amazing that we have to do sleuthing to figure out how to get Java to bloody work. It’ll be good when it has fully transitioned out of Apple’s hands.

To do this, open Java Preferences, select the runtime(s) you use (in the General Tab), then click Options… and just paste that in.