I am heavily confused between the Iris Pro and the Nvidia models.
In the meanwhile I read many posts - Like the radeongate and the famous issues with Nvidia gpu too - overheating and display freezing. So at the end I though of sticking with Iris Pro Model. But I have a question - What if I get the Nvidia model and the gfx app that allows to forcefully use one of the GPUs? That should be cool right ? Use Iris Pro almost all the time and only during gaming shift to Nvidia. I have no plans of using bootcamp/windows. Mac Os all the way.
Hopefully by doing this I can prolong life of my mac. :roll eyes:
.....
by dusk from here
I tried to put in all the pros and cons that came to mind. Feel free to edit errors or rephrase or add points.
Benefits Iris Pro only model
+ lowest power use: system powers down based on load, the dGPU would still stay active even if iPhoto is open in the background just sitting there
+ better power efficiency for presentation use. External always triggers dGPU even if you only show slides
+ Quicksync is available in Windows for ultra fast video encoding with Handbrake, it is simply not possible to enable Iris Pro in Windows natively and quicksync does not work in a VM
+ better performance in OpenCL, GPGPU situations
Downsides Iris Pro only model
- lower performance due to worse drivers for gaming
- under medium to high load Iris Pro is often less efficient than the 750M
Benefits dGPU option
+ better gaming performance but only about 30% unless the Intel driver has serious problems
+ power efficiency under load
+ still some Cuda code paths that offer extra performance but this is dying out and evidence of benefits is scarce
Downsides dGPU option
- everything under + Iris Pro only option
- the 750M is extremely outdated. Iris Pro and 750M are almost equal in performance (0-30% diff), 850M is twice as fast (which is much more than the usual 30-40% a new generation usually offers) and the 950M is still 20% faster both are available in current Windows notebooks. Just don't buy a 15" MBP currently if the Iris Pro only option does not appeal to you. It is horrible value for the price.
- there have been replacement programs for various troublesome dGPU models in the past. Most troublesome 8600M due to Nvidia fault, 6750M, 650M and some current due to Apple production issues.
What aren't issues?
Heat: Without load the 750M is cool enough never to pose a problem, with load the dGPU is often even cooler because the heat is spread over two chips. Also the TDP of the 750M is fairly low and it steals TDP just like Iris Pro form the CPU cores. With no GPU load the 2.3Ghz CPU runs at 2.8-2.9Ghz with normal room temp after a heat up period. When either GPU is at a higher load the CPU speed drops until it runs at only 2.3Ghz. Regardless which GPU is active, both result in the same behavior. Also note that at 3Ghz TDP is 40W while at 2.3 Ghz it may only be 18W for the CPU cores. TDP climbs quickly around 3Ghz. The cooling system in the MBP is not built to support the full 47W of the CPU while the 750M is at full load (about 25W).
___________________________
By Apoorv
Correct - As you said - Cool if you are getting the Iris Pro Model otherwise the dGpu is just not worth it.
And my bad but what does TDP mean ?
thermal design power or the way I used it just the heat dissipation in W
In the meanwhile I read many posts - Like the radeongate and the famous issues with Nvidia gpu too - overheating and display freezing. So at the end I though of sticking with Iris Pro Model. But I have a question - What if I get the Nvidia model and the gfx app that allows to forcefully use one of the GPUs? That should be cool right ? Use Iris Pro almost all the time and only during gaming shift to Nvidia. I have no plans of using bootcamp/windows. Mac Os all the way.
Hopefully by doing this I can prolong life of my mac. :roll eyes:
.....
by dusk from here
I tried to put in all the pros and cons that came to mind. Feel free to edit errors or rephrase or add points.
Benefits Iris Pro only model
+ lowest power use: system powers down based on load, the dGPU would still stay active even if iPhoto is open in the background just sitting there
+ better power efficiency for presentation use. External always triggers dGPU even if you only show slides
+ Quicksync is available in Windows for ultra fast video encoding with Handbrake, it is simply not possible to enable Iris Pro in Windows natively and quicksync does not work in a VM
+ better performance in OpenCL, GPGPU situations
Downsides Iris Pro only model
- lower performance due to worse drivers for gaming
- under medium to high load Iris Pro is often less efficient than the 750M
Benefits dGPU option
+ better gaming performance but only about 30% unless the Intel driver has serious problems
+ power efficiency under load
+ still some Cuda code paths that offer extra performance but this is dying out and evidence of benefits is scarce
Downsides dGPU option
- everything under + Iris Pro only option
- the 750M is extremely outdated. Iris Pro and 750M are almost equal in performance (0-30% diff), 850M is twice as fast (which is much more than the usual 30-40% a new generation usually offers) and the 950M is still 20% faster both are available in current Windows notebooks. Just don't buy a 15" MBP currently if the Iris Pro only option does not appeal to you. It is horrible value for the price.
- there have been replacement programs for various troublesome dGPU models in the past. Most troublesome 8600M due to Nvidia fault, 6750M, 650M and some current due to Apple production issues.
What aren't issues?
Heat: Without load the 750M is cool enough never to pose a problem, with load the dGPU is often even cooler because the heat is spread over two chips. Also the TDP of the 750M is fairly low and it steals TDP just like Iris Pro form the CPU cores. With no GPU load the 2.3Ghz CPU runs at 2.8-2.9Ghz with normal room temp after a heat up period. When either GPU is at a higher load the CPU speed drops until it runs at only 2.3Ghz. Regardless which GPU is active, both result in the same behavior. Also note that at 3Ghz TDP is 40W while at 2.3 Ghz it may only be 18W for the CPU cores. TDP climbs quickly around 3Ghz. The cooling system in the MBP is not built to support the full 47W of the CPU while the 750M is at full load (about 25W).
___________________________
By Apoorv
Correct - As you said - Cool if you are getting the Iris Pro Model otherwise the dGpu is just not worth it.
And my bad but what does TDP mean ?
thermal design power or the way I used it just the heat dissipation in W
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