I know there are plenty of threads about iMac RAM, but I had a quick question. I am considering between two kinds of RAM: http://www.macmall.com/macmall/shop... Pros and Intel iMacs-Notebook Modules Memory https://eshop.macsales.com/item/Other World Computing/5300DDR2S2GB/ The Mushkin RAM says it is PC2-5300. The OWC RAM says it is PC-5300. Is there a difference between PC and PC2? Which RAM should I get? thanks.