Woody1999 :
No, the PC would still recognise it as 12GB of RAM. If you have a newer motherboard then you probably you have one pair of RAM sticks running in dual channel and a single RAM stick running in single channel.
Are all the sticks the the same brand, the same speed and the same voltage? If not you may have issues.
Woody
all the same speed and voltage but 1 stick is a different brand, was a quick fix till pay day, bought GTA but with 8gb of ram I get up to 85-92% memory usage and the entire system lags, making it really had to play games, bought 1 stick off of amazon until pay day when I getting a 16gb corsair kit.
the system is telling me I have 12, but I can't change it to let me use that, and CPU-Z is saying I'm running in single channel.
Should I hold off buying the kit till I know for sure it will work, or is it likely to be compatibility issues and should be fine with a kit