Different ram stick sizes

Alright so I upgraded my ram from 2gb (4x512mb sticks, I have 4 slots), to 6gb(2x1gb and 2x2gb), when I bought the 6gb slots I was careful to ask for same voltages, frequencies etc, but Im still not sure if this different size ram sticks thing will affect the overall performance.
So here's what I got from speccy:
http://imageshack.com/a/img923/9472/61strc.jpg

So will the difference between sticks affect performance that much?
cpu-z says I'm running on dual channel symmetrical

Welcome to the forum.
Please edit your profile with all hardware specs.
The 1G and 2G stick are from different manufactures and has different latency, and this can cause some problems.
Normally you have two channels, A & B. I Suggest you to install 2G on channel A and B (slot 1 and 3 ?) and 1G on channel A and B (Slot 2 and 4 ?) in order to have same amount in both channels.
You have to read your MB specification to find out witch slots are from channel A and B.