Hey everyone--let me preface this post by saying i've been perusing macrumors for a while now--and i love macs. But I have some questions about the Core 2 Duo's architecture and clock speed. I recently bought a 24 inch iMac with 2.16 C2D, 2GB ram, 7600gt and 500gb HD. I spent 2,300 with my educational discount. For 1,800--I could put together a custom PC with an AMD x2 4200ghz and 7900GT and a 24 inch samsung monitor. I am curious about the clock speed/architecture of the Core 2 Duos. Mine are set at 2.16 ghz, but is that 2.16 ghz equivalent to an Intel pentium 4 2.16 ghz? Or are the Core 2 Duo's like the AMD chips where the clock speed might be at 2.6ghz, but it will run like an Intel 4.2 ghz? Could someone clarify the clock speed/architecture difference between the Core 2 Duo's and say, Intel pentium 4s or AMD chips? I'm essentially wondering if I could return my imac and spend 400 dollars less on a computer that would be double the performance of the iMac. And although it would be lame going back to windows after using wonderful OSX, I simply cannot justify the 400 price difference, especially if a cheaper PC machine would outperform my imac. Thanks in advance!