ram upgrade options

[Simiishthis]

Hi guys, one of my ram just died. My mobo is a asrock b75 pro3-m which supports dual channel ddr3. The remaining ram is a stick of gskill 4gb ddr3 1333 ram.
Should I get 2 stick of dr3 1333ram to make my rig 12 gb? Or replace all with 2 sticks of 4gb dr3 1666? Whats the best configuration and where can i get it at the best price?

Anyways what does dual channel ddr3 meant?

Thanks!

 

[ArcticCheetah]

RAM Died = RMA RAM due to lifetime warranty.
If you want to up the specs you can try thaiphoon to flash your RAM SPI, if it doesn't work just flash back.

 

[Simiishthis]

Hi i think the shipping costs will not be worth it... I rather buy new sticks. What are the recommended course of action?