Merom in Apple's notebooks, some thoughts...
Merom (Core 2 Duo) processors are coming to Apple's notebook lineup this Autumn, but they've already appeared in test system PC notebooks. And there's a general agreement among testers, which we have to look at. Merom brings about 20-25% more performance, but battery performance is lower when using Merom. Not much lower, but a bit. At its idle speed of 1.0 GHz, both Yonah (Core Duo) and Merom (Core 2 Duo) use about 36 Watts, but even there, the newer chip uses a tiny bit more. Under heavy load, the difference gets bigger. This means that the new chips won't mean cooler MacBooks and MacBook Pros, because Apple won't clock them below their predecessors.
What the new chips do
bring to the table are mainly two things, then: 64bit support and faster performance, mainly because of a larger cache. Comparing 2.16 GHz MacBook Pros, one using Yonah, one Merom, you'd get a performance increase of anything between 10 and 25% (depending on application, of course), but you'd also lose about 5-10% of battery life. Apple could theoretically change the battery in the notebooks, of course. And newer graphics cards might make the difference in performance (but also battery life) bigger. We're certainly looking forward ot Apple's Autumn line-up of notebooks, but it's not going to be the biggest step just yet.