u can try this,
1. Currently QV appears to be using only 1GB RAM of my system. Would it help to supply more RAM? (If yes, how can i do this - on my local system i have 8GB, only 3,5GB are used when my application is running).----> System properties--Advanced tab---Performance settings---Advance tab--click on Change button and try to adjust ur ram seeings for local system.
Based on what you said, you can't expect much from a machine with 8GB. Also bear in mind that processor is very important when redenring/calculating all charts. If you have complex expressions and maps, then this will affect the processor and RAM. Once calculated, RAM will be affected.
I would highly recommend you go over your expression and make sure you make them as simple as possible. There are plenty of techniques you can use. for example, putting as many of your calculations as you can in your script or as you mention using set analysis (although is not always the solution).
If you want to know more about set analysis, please follow this link: Set Analysis: syntaxes, examples