Intellij IDEA very slow while typing in editor (Scala only)

Question

Using IDEA 14.1.5 ultimate edition in Scala project there are a lot of performance problems. After typing a several symbols in the editor I have a lag for a few seconds. This happens only in Scala project (big project), in Java project everything is fine.

Core i7 4770, 16Gb RAM, projects located on SDD disk

vm.option have the following settings

-Xms750m
-Xmx8192m
-XX:MaxPermSize=1024m
-XX:ReservedCodeCacheSize=225m
-XX:+UseConcMarkSweepGC
-XX:SoftRefLRUPolicyMSPerMB=50
-ea
-server
-XX:+UseCodeCacheFlushing
-XX:SoftRefLRUPolicyMSPerMB=50
-Dsun.io.useCanonCaches=false
-Djava.net.preferIPv4Stack=true

It's very terrible. I try to turn off all inspections, autocompletion and version control (!!!), but it doesn't help. I'm thinking of starting working in notepad.

Can anyone help me? What else should I turn off to increase perfomance?

upd: I found that turning off junit plugin give me some performance, but i have a "little" problem - gradle plugin require junit. I'm using a last version of all plugins and I can't update to version 15, because I have a licence for version 14.

I can't understand how and why any plugin can leads to performance degradation for editor(!). Why I can't turn off all edit handlers? This IDE designed for text edit? I really feel performance problem, and this give me lot of pain in this case.

Answer 1

I usually disable type-aware highlighting and set the inspection level to syntax only. That helps a lot, especially in case of string interpolations and Spray.io routes with complex implicit marshallers.

java/idea/bin/idea64.vmoptions

 -Xms256m
 -Xmx1024m
 -XX:MaxPermSize=350m
 -XX:ReservedCodeCacheSize=225m
 -XX:+UseConcMarkSweepGC
 -XX:SoftRefLRUPolicyMSPerMB=50
 -ea
 -Dsun.io.useCanonCaches=false
 -Djava.net.preferIPv4Stack=true
 -Dawt.useSystemAAFontSettings=lcd
 -Dhidpi=true