iMac 21.5' 4gb vs 8gb Ram?

[lhayati]

Hey,

I have a dual core 3.06ghz iMac with 4GB of ram. I am experiencing lagg in applications such as iMovie 11, is this to do with the processor or insufficient ram?

When I check activity monitor I usually have about 100 - 200mb free ram, but it says 1GB inactive, why is this?

So should I upgrade to 8GB? Currently it has 2x2gb, so would it be better if I buy another 2x2gb or a 1x4gb?

Thanks,
Louis

 

[smoge]

If your using and making large files in imovie then it mite be the ram, How much free space do you have on your HDD?

 

[lhayati]

400gb, so I don't think it's got anything to do with that.

 

[smoge]

I as baffled as you then.