Thinkpads Forum

I own a T520 with integrated graphics. The thermal solution appears to be shared with the W series and perhaps overspecified for my model. The machine is exceptionally quiet. I really like that, but I'm tempted by the IPS screen of the T540p. If, for the sake of the argument, one were to buy a top-end T540p with quad-core processor and nVidia graphics, would there be any drawbacks in terms of power and thermal requirements, such as:

Louder or more persistent fan noise? I care more about idle behaviour than when it's under full load. I guess with all the power saving measures of modern CPUs, e.g. Haswell, this is not a concern, or is it? How do the nVidia 730 graphics stack up in that regard?

Can the nVidia GPU be temporarily disabled in favour of the integrated graphics? Any Optimus bugs / issues?

I note the quad core processors are rated for 47W TDP, as opposed to 37W. Sometimes machines with high-end parts have throttling issues. Are there any known ones for the T540p? How about when both the CPU and nVidia GPU are used at the same time, such as when playing a game?

Would a larger power supply be required for a top-end machine? What wattage? Are there any known throttling issues with the standard (65W?) power supply?

I found some answers regarding power supplies:

http://forum.notebookreview.com/lenovo/ ... tions.html

Really all you have to do is watch how the power supply changes when you change machine configuration. I hadn't realised that.

There are reports of severe throttling...I believe I've seen them both on LF and NBR...