Feed the Beast doesn't allow me to use more than 500 mb ram

[JanikkinG]

Hey guys,

I have a pretty annoying problem here. I downloaded FTB a couple of days ago, and set the slider of RAM to 2,5GB. But when i started playing, I noticed lag spikes after a couple of minutes of playing. Yesterday I discovered that FTB only uses 500 mb RAM, and when it reaches that limit I have a lag spike. When I try to increase my maximum amount of RAM through the JVM Arguments, I get this error:
Error occurred during initialization of VM
Incompatible minimum and maximum heap sizes specified
Picked up _JAVA_OPTIONS: -Xmx512M

Could someone help me with this?

Full log: http://pastebin.com/4k8c4TPT

 

[NEXUS2345]

Right, if you go into control panel and click on Java, it will give you some settings. Go through those and make sure that any JVM argument boxes are empty.

 

[JanikkinG]

Right, if you go into control panel and click on Java, it will give you some settings. Go through those and make sure that any JVM argument boxes are empty.

Thanks for replying!
But I can't find anything about JVM arguments in the Java Control Panel.