* Of course it was worse than 1GB if the Mac only has 4 GB, you aren't leaving anything for OS X, this conflicts with running the VM. Don't forget the computer is now running two OSes in parallel and you have to have a value that balances the 2.
*It doesn't matter how big the app inside is, we are talking about the load of the whole OS.
* I suggest you try to assign 1.5 GB to the VM. More than that will make everything slower because the Mac side will have too little RAM. You can try closing apps, specially internet browsers with many tabs, on the mac side to free up RAM.
* I should mention that 4 GB RAM on the computer is the absolute minimum to run Parallels, I normally recommend at least 6 GB, in order to give 2 GB to the VM and 4 GB to OS X, OS X Mavericks likes a lot of RAM.
Last edited: Jan 31, 2014