I will be upgrading or close to maxing out the RAM in my computer. Not sure why I need it but just want it since RAM is so cheap now a day vs Hard Drives. I am doing virtualization such as using Virtualbox.

Out of curiosity:

Currently, I have this motherboard and RAM setup:
http://www.gigabyte.com/products/pro...d=3450&dl=1#sp
http://www.newegg.com/Product/Produc...82E16820227365

That is exactly what is in my computer right now. So here are the questions:

-Should I buy another 12gb and can they be different in volts and speed?
or
-Should I toss the current 6gb and just buy a 24gb deal? Why? Well, in this thread, it basically recommends not to mix ram types.
http://www.tomshardware.com/forum/23...-latency-volts

-My board recommends putting 1.5V but the current ram is 1.65V. I should buy RAM that runs at 1.5V? I know when buying RAM, we need to look for the lower the better, interms of latency and voltage.

-Is it better to have 12gb of 2000mhz or 24gb of 1600mhz?
Please feel free to make recommendation from this:
http://www.frys.com/search?cat=-6903...play&fq=100515 Triple-100514 12-100512 PC3__16000_/_2000MHz
http://www.frys.com/search?cat=-6903...play&fq=100515 Triple-100514 24-100512 PC3__12800_/_1600MHz