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When purchasing a new MBP I want to optimize it for mobile usage.
There are different quad-core i7 processor available for the 15'' MBP. See the list here. While they have different features, all of them have the same maximum thermal design power:
- How does their power drain compare at their base frequencies?
- Will a processor of the same generation, but lower base frequency, draw less power?
Modern processors spend most of their time not working. E.g. when you're using a word processor, up to 90% of the time between keypresses your CPU will be asleep. Faster processors will spend more of their time asleep. Spending 90% of the time at 0 Hz makes the notion of a "base frequency" quite meaningless. – MSalters – 2012-02-23T12:26:27.913
I don't understand. I've never noticed my CPU not working. I have a CPU monitor currently running and it's never 100% idle. – None – 2012-02-23T12:39:49.160
The feature is intentionally not noticeable. The CPU is not in a "deep" sleep, so it can respond immediately. As you note, your CPU is often 90% idle - that's the average over 1000 milliseconds. In practice, this means it's 100% idle during 900 milliseconds, and 100% busy during the other 100 ms. – MSalters – 2012-02-23T12:44:17.330
Ah ok. So would you assume, that the high-frequncy processors would consumer less power overall because they sleep more? – None – 2012-02-23T12:47:03.863
No, because this is precisely offset by their higher power draw when they're not asleep. See my answer. – MSalters – 2012-02-23T12:53:22.340