Real-world difference between Penryn and Nehalem?

[ThomasJL]

In terms of real-world performance, what would the difference be between a current aluminum MacBook and one with the first incarnation of Nehalem?
(This question assumes that both machines are using the exact same aftermarket SSD, the exact same version of Snow Leopard with all options installed by a clean install, and the exact same amount of the exact same brand of RAM.)

[fifthroot]

I think any difference would have to be measured by application performance, rather than general OS performance. That means high-resolution Photoshop stuff, video rendering, etc.

I don't think you're going to see any difference with regard to iTunes, web browsing, word processing, or web design. Maybe games. Maybe. In a few years.

[iMacmatician]

In terms of real-world performance, what would the difference be between a current aluminum MacBook and one with the first incarnation of Nehalem?
(This question assumes that both machines are using the exact same aftermarket SSD, the exact same version of Snow Leopard with all options installed by a clean install, and the exact same amount of the exact same brand of RAM.)Just like not only are all Penryns not created equal, neither are Nehalems. The Nehalem benchmarks being thrown around are with the Core i7 variant, which is for high-end desktops. The mobile Nehalem has less new features than Core i7.

Core-wise, clock-for-clock, Nehalem gives 15%-20% higher performance over Penryn. Other parts of the CPU partially account for the extra difference. Also, it depends on the type of task (single-threaded performance is 1.1x to 1.25x as fast, multi-threaded performance is 1.2x to 2.0x as fast).