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While looking for a new laptop, I found out that the CPUs in laptops are usually less powerful (in terms of speed) than in desktops.

As an illustration, in one store I was offered a choice between a desktop with core i7 6700 and a laptop with core i7 6500U. Here is a detailed comparison between these CPUs. In general, the 6700 is much faster, but the 6500U has much lower power-consumption. Another example is core i3 6320 vs. core i3 6100U: the former is faster while the latter uses much less power.

I intend to use the laptop at home, and only occasionally outside. So, I prefer a laptop with the faster CPU. However, in the cases I take it outside, I do want to be able to tell it to act slower and with less power consumption. Is it possible to construct a laptop with high-speed CPU like i3 6320, and then occasionally tell it to "behave like i3 6100U"?

EDIT: I intend to install Ubuntu on the laptop. I do not know if this is relevant for the question.

Dave
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Erel Segal-Halevi
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1 Answers1

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Yes and no (mostly no).

A better comparison of the i7 CPU's is here - and you can do similar comparisons for most Intel CPU's. You will note that the 'U' version has half the cores, half the threads and a much lower TDP.

'U' CPU's are specifically designed and optimised ON THE DYE for low power consumption, where the regular ones are designed for performance. As the dyes are different, the performance characteristics must be as well.

You can do some things to reduce the performance of the faster processor to give back some juice - most noteably underclocking it - however most OS's will do this automatically anyway. [ Its notable that the U series typically run at a lower clock and only burst to there max frequency ]. You can also try and undervolt the processor, but this can cause instability.

None of this is going to get you from 65 watt TDP to anywhere near 15 watt TDP.

Note that not all laptops use "U" CPU's - these are typically "ultra-low" power - and you can get CPU's which perform much better in Laptops - Here is a list of CPU's - if you get a laptop with a 45 watt TDP it will perform a lot faster then a U series at 15 watts -

For example the i7-6700HQ gives a passmark (relative speed score) of 8039, almost double that of the i7-6500U at 4327 - but the battery won't be as good on it.

davidgo
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