PhpStorm very slow and sluggish on netbook, optimize IDE for responsiveness?

I recently upgraded from PhpStorm 6 to PhpStorm 7. Delighted to see all the improvements, but it runs awfully slow on my low-powered netbook. The delay between typing and seeing text appear is often 5-6 seconds and gets worse as line count increases. It is unusable at this stage.

How can I improve the general IDE speed and responsiveness?

Edit 2017: You may first want to try experimenting with allocating PhpStorm some more RAM if available. Do this by

1. Going to Help -> Edit Custom VM Options
2. Change -Xms and -Xmx to be something reasonable for your hardware. I have -Xms512m and -Xmx2048m on an 8GB RAM laptop.
3. Restart PhpStorm.
4. If you want to see how much RAM PhpStorm is currently using, you can go to File -> Settings and search for and enable show memory indicator.

Original answer: I made some changes to increase the responsiveness of the IDE. I'm sure there are more things one could do, but I found these to improve the performance to well within usable margins. From most effective to least:

1. Disable language injections: File -> Settings -> Language injections. Untick as many boxes as you're comfortable with. HTML was the real killer for me.
2. Disable inspections: File -> Settings -> Inspections. Untick as many as you don't need.
3. Disable unused plugins: File -> Settings -> Plugins. Untick unused.

These changes brought down both the startup time and significantly increased responsiveness of the IDE in general.