Selecting Processors for Your Lion Server Hardware
When determining specifications for Apple hardware to run your OS X Lion Server, you can’t choose just any processor the way you can with PCs. To get a particular type of processor, you have to select the Mac model. Within each model are some differences in clock speed. Mac Pro offers the most options in processors at purchase time, giving you a choice of one or two multicore processors.
Processors with multiple cores act as multiple processors. So two dual-core processors are equivalent to one quad-core processor. This is why processing power is sometimes described in terms of the number of cores rather than the number of processors.
You don’t need a brand-new Mac for Lion Server. An older Mac is perfectly fine — as long as it has a 64-bit Intel processor. Lion won’t run on the older PowerPC processors.
Sometimes, the Mac’s model name gives it away: A Power Mac has a PowerPC processor. All Mac Pro and MacBook models use Intel processors. Mac minis, iMacs, and Xserves, however, came in both PowerPC and Intel processor versions. When in doubt, check the About This Mac window, accessible from the Apple menu. This window also reveals how much memory you have in the machine.
For most Mac models, you can’t upgrade a processor. You can upgrade a processor in Mac Pro, but doing so is difficult and voids the warranty. For a Mac Pro no longer under warranty, check out this website:
Here, you can find information for various releases of the Mac Pro from 2008 and earlier to more modern models.
Only the Xserve has an officially upgradeable processor. Apple still has directions at its support website: search for Xserve processor. You find PDF documents for each Xserve revision, such as Xserve (Early 2008) DIY Procedure for Processor (Manual).
You can’t upgrade a PowerPC Mac with an Intel processor. The architecture of the machines is just too different. Don’t even try.