This is not about gaming performance. I've got that all sorted when booting into Windows.
This is a 2012 version rMBP.
The question is about trying to gain a little more control over the hardware from the OS X-side.
During the summer, the machine runs acceptably cool under typical usage, for example, web browsing, even mp4/h.264 (non-flash) video decoding, etc. I was watching a 1080p Blu-ray rip the other day. Handled it fine.
However, once I plug in my external 2560x1440 display via a MiniDP-to-DL-DVI adapter, the display will only connect if the GT 650M is switched on. I use gfxCardStatus to control whether this Nvidia GPU is allowed to be switched to.
So this is fine, except that now I have to keep the fan spinning at higher RPMs (controlled through smcFanControl, of course), and even with that the temperature reads above 70 degrees C most of the time. It will generally be in the mid 50's to low 60's range when running the integrated GPU.
I know these are not very specific numbers, but the point is that whenever the Nvidia GPU is powered on the machine is producing a lot more power as heat.
According to an app I have here called "BatteryExpert" it draws around 11 watts on integrated and 19 watts with the second screen plugged in.
So my question is how can I see the clock speed of the Nvidia GPU, and how can I adjust it in hopes of cooling it down, but still keep it enabled? I need it to be powered on for the secondary monitor, but it's making the aluminum surface a bit too warm for comfort for typing.
I am able to boot to Windows to run e.g. GPU-Z there to check the clocks, but on Windows I'm not aware of any app that can read out a power draw wattage, so it's a little difficult to corroborate. (I guess I can compare idle temps, though.)
It may turn out to be the case that that ~8 watt difference (which results in the 15+ degree C difference in temperature, and a similar difference felt on the aluminum surface) is fully accounted for by running the 650M at its lowest power level, as it is after all a ~50W unit. I'm not really sure what to think. On the one hand 50W is at 900Mhz under load, and here it should be ~165Mhz ('s what GPU-Z tells me in Windows) idle.
Well I've gone off in the weeds at this point. The question is, what is some monitoring software to show me the GPU clocks? When I tried iStat Menus it did not have a GPU clocks reading.