Are the dual core intels on the macs the same as the pc intels? If so, why does a 2.0 ghz mac http://store.apple.com/1-800-MY-APPLE/WebObjects/AppleStore.woa/wo/0.RSLID?mco=EDB278F7&nclm=iMac cost almost the same as a 3.0 ghz http://www.dell.com/content/products/features.aspx/cto_xpsdt_600?c=us&cs=19&l=en&s=dhs pc?