I5 Mobile Turbo Boost Mechanics

rub2106

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Apr 14, 2010
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Hoping someone can verify a theory regarding turbo boost for me. I'm debating between an i3-350 and an i5-430. The obvious difference is the turbo feature and I'm trying to assess the expected benefit. I've seen the benchmarks showing that it's more powerful but can't see anything to explain it other than the turbo boost which makes it helpful to know how often you can expect that feature to kick in.

If I understand correctly, the mobile i5 processors can enter the turbo boost state provided that there is power and temperature room left to support it within the desired operating parameters. In addition, the line includes an integrated video processor which is included in those calculations. So, is it reasonable to assume that an i5, if properly ventilated, would likely be able to enter the turbo state at all times if paired with a discrete graphics card? This would seem to make sense as you wouldn't have the integrated gpu active which should clear up power for the processor.

Am I on the right track here? Thanks for any thoughts.
 
Solution


In many notebooks, the GPU and the CPU are connected to the heatsink and fan assembly by a single heatpipe - so the die of both chips are directly connected by copper. This can make cooling your CPU difficult as well.
Yes, you are right on with your theory. Both the i5 and i7 series have the turbo feature. Combine what you said with the demands of what you are doing, i.e. running a CPU intensive game or multitasking, the CPU along with the chipset, will detect if the program(s) need more frequency (speed) to run faster and more efficiently. Like you said, generally the cooler/more ventilated you can keep a laptop with an i5 or i7, the more likely the turbo feature will kick on, but not always. Remember, the other variables you mentioned like graphics card use and power use are generally things that you cannot control.
 

rub2106

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Thanks for the response. You covered part of what I'm looking for. Let me refine the question a little bit.

All other things being equal, would the processeor be capable of entering turbo mode more frequently with a dedicated video card than without?
 

lotri

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I think it would depend on how powerful of a dedicated card you were looking at. The more powerful it is, the hotter it would run, and the less likely the turbo boost would activate. It would also depend on the cooling solution you utilize for your laptop.

For example, my Dell has 2 fans which keeps temps below 60C when I'm gaming (on old hardware though). My friend's HP dv6, however, only has one fan.. which can lead to some heat issues under load.
 

rub2106

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Interesting. I hadn't considered additional case heat generated by the video card as a significant issue. My thoughts were based on the the processor package only. The machine I was looking at with in i5 is an Acer which seems to have a reputation for making machines that run on the hotter side. The boost may not be as much as I was hoping then.

Thanks.
 

frozenlead

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In many notebooks, the GPU and the CPU are connected to the heatsink and fan assembly by a single heatpipe - so the die of both chips are directly connected by copper. This can make cooling your CPU difficult as well.
 
Solution