The latest MacBook Pro refresh finally brought Intel Core i5 and Core i7 CPUs to Apple’s line-up of laptops… but only the 15 and 17 inch models. If you want a 13-inch MacBook, you need to satisfy yourself with the Intel Core 2 Duo chipset.
Steve Jobs claims that the reason Apple went with the Intel Core 2 Duo chips for the 13-inch MacBook Pros because a 20% CPU increase was outweighed by giving the 13-inchers a much better CPU and 10 hour battery life.
But Ars Technica has a more in-depth explanation: price, graphics performance, battery life and the laws of physics.
Basically, here’s the argument: not only would the Arrendale series of processors have pushed the price of the MacBook Pro 13-inch higher than Apple wants it to go, but the choice of Core i3 CPUs, as well as Intel’s integrated graphics HM55 chipset would have left no room on the 13-inch logic board for a discrete GPU. Apple could have made the logic board larger, but it would have left less room for a bigger battery.
Makes sense to me, although you’ve got to wonder if this is going to hobble the 13-inch MacBook Pros CPU going forward, or if Apple will eventually cave and reduce battery life to keep their laptops competitive CPU-wise.