Noise - Mobile CPU vs Desktop CPU

I've always gone with mobile CPUs in the past, but I'm considering going with a desktop CPU when Skylake comes out. My question is: are laptops with desktop CPUs significantly noisier than those with mobile CPUs?

Obviously they run hotter under full load, but do they actually hit that load as much is typical usage since they're more powerful chips? And is there a way to underclock them if, in some situations, you're more concerned about noise than performance?

Thanks!

 

You may notice more noise since you sit closer to a notebook exhaust port vs a desktop which is usually on the ground away from you.

 

You may want to re-read the question. A Doh! moment

There's a lot of good info in the owner's lounges for the desktop CPU models. You can underclock. I believe Intel XTU will let you save profiles. Undervolting will bring temps down even more.

 

Noise purely depends on cooling system design, not on if CPU is labeled "desktop" or "mobile".

My P751ZM with desktop CPU is about 3 times quieter than P15xxM with mobile CPU were.

 

http://www.notebookcheck.net/Schenker-XMG-U505-Clevo-P751ZM-Notebook-Review.134638.0.html

Under System Noise they have compared a P751ZM with two P505s - one an SG (the Pro) with 980M and the other with 970M. You can see that the GPU makes quite a difference in maximum noise level but that actually the U505 / P751ZM runs a little quieter at idle and more noticable quieter on load (though this is mainly GPU weighted load in the notebookcheck Noise Level tests).

With the thicker chassis required to accomodate the desktop CPU and to a point MXM GPU, you have a more powerful cooling system to cope with the higher temperatures on load. This also means that at idle the better cooling system is quieter.

As Bullrun mentioned, it is very easy to undervolt the CPU a little in Intel XTU. The 4790K (88W) will benefit from this most, though if you don't want to start fiddling with settings then the 4790S (65W) in the above review runs cooler and is only 11% less powerful.

It completely depends what you use the laptop for. In a very CPU intensive game like GTA V you will generally see 40% CPU usage across most of the cores and high running temperatures. Most other games which are less CPU intensive won't run the CPU as hard and you'll see much lower operating temps.

 

Great info -- thanks!

 

You can also have an XTU profile to limit the TDP if you need it quiet at certain points. Limited to the same TDP the larger heatsink will make the desktop machine quieter.