Mac vs. PC is a never-ending debate, but when it comes to video editing, what we need are hard and fast numbers. It would be impossible to generate a comparison of apples to apples (zing?) by using Final Cut Pro, since that NLE is only available on one platform. Instead, Adobe's CS5 suite is the ideal candidate -- and considering CS5 is 64-bit native on both OSes, it should be a fair fight. The best way to settle this would be to open the exact same CS5 project file on a Mac and a PC, play it back, render it out, and measure it in other ways -- on various machines, at different price points -- and compare the results. If only someone would create such a benchmarking tool and upload the results to a database... As it turns out, someone has done just this.
As part of a recent online workshop I attended virtually, Adobe's Karl Soule mentioned that PCs seem to be getting 3-5% better performance in CS5 than Macs. I tracked Karl down afterwards and asked him why this was the case, and while he didn't offer an explanation for the 3-5% difference, he did say that PCs blow past Macs when it comes to super high-end configurations -- presumably, the new Mac Pros will alleviate this discrepancy.
I consider myself a technical person for better or for worse, and I'm well aware I spend way too much time using and talking about computers. However, when it comes to the vast untamed expanses of the internet, there are wayyy nerdier folks out there. Some of these nerds (absolutely no offense intended, Bill Gehrke and Harm Millaard) have put together a site specifically for benchmarking Premiere Pro, giving it the unfortunate name of PPBM5. Naming decisions aside -- the acronym sounds like it was imagined by a scatalogical toddler -- the site has the potential to answer a number of performance questions for editors. If you're looking to configure a PC for editing in CS5, this is a great resource, with real-world benchmarks across a number of different hardware configurations. They've even compared different nVidia GPUs (the purple bar is the one of interest, shorter is better):
Despite the fact that it's not "officially" enabled yet (you have to apply this hack for now), the best price-performance GPU is the recently-released GTX 480, which retails for just shy of $500 and bests the $1,700 Quadro CX (which is a generation old). The GTX 480 is PC-only right now, but it was rumored to be in the works for the Mac. We'll see if it ever arrives, given it's apparently going to be absent from the new Mac Pros.
Regardless of video card, there are no hard Mac numbers in the database right now because, as PPBM5 states, "there might possibly be a Mac version, we are looking for beta testers." So: do you have a Mac? Do you have CS5? Drop them a line and let them know you'd like to be a beta tester. Run the benchmark and let's see how the two platforms compare when it comes to editing efficiency.
I suspect the best of both worlds (meaning, PC pricing, with the Mac OS) would be to build a hackintosh specifically tailored for editing in CS5. If I built such a machine for my own editing needs (and for my budget), would you be interested in a how-to post here?