MacBook Pro 15" 2015 mainly for Windows - which GPU to choose?

[magbarn]

Since the early benchmarks show the m370x actually has higher power consumption than the 750m along with the requisite higher heat, the iGPU only version will be much quieter in windows. My 2012 rMBP in Windows 8.1 definitely runs hotter with the fans audible as the dGPU is forced on. Looks like a forum member here has a found a 'hack' to switch the iGPU in windows, but that process sounds complicated. For your purposes that you want to use the machine for the iGPU will be more than enough AND you'll have the biggest chance of having a rMBP 15 that will last at least 5 years or more without a logic board swap (that only temporarily fixes the problem) I have a feeling the late 2013/2014 models will eventually head for a extended warranty too down the line as there's hardly any difference between a 650M and a 750M.

 

[yjchua95]

I feel that we have basically covered the "battery aspect" of Iris Pro vs M370X but what about heat and fan noise? Since the M370X consumes more energy it produces more heat, but does that mean that that you have more of a problem with fan noise on a M370X system or is it no noticeable difference as long as we are talking about idle or low system load? Personally, I don't really worry that much about an hour more or less battery time since this is a power laptop, but if the fan would kick in all the time it would be more of a problem. I'm mostly interested in Windows use as I assume this isn't really a problem in MacOS.

One thing that puzzles me though, why does it seem to exist a "GPU switch" software for the MacOS since MacOS should be capable of managing switching between GPUs by it self kind of like Optimus on Windows?

Actually when doing intensive tasks (I simulated it with macoh stress tests), the rMBP ran cooler with the dGPU active compared to the one with only Iris Pro. This is because tasks are spread out across two chips instead of one.

GPU switching isn't possible under Windows as Apple uses a custom implementation of UEFI 2.0, and the UEFI will disable the dGPU when booting into Windows. Unless you can rewrite and flash the UEFI, GPU switching isn't gonna happen anytime soon.

 

[improwise]

Actually when doing intensive tasks (I simulated it with macoh stress tests), the rMBP ran cooler with the dGPU active compared to the one with only Iris Pro. This is because tasks are spread out across two chips instead of one.

GPU switching isn't possible under Windows as Apple uses a custom implementation of UEFI 2.0, and the UEFI will disable the dGPU when booting into Windows. Unless you can rewrite and flash the UEFI, GPU switching isn't gonna happen anytime soon.

Yes, I read about that in another review, and it seems logical since you most likely can user more cooling with 2 separate chips compared with distance between then rather than stuck together. Do you have a feeling if this is true for non stress tests as well, that the M370X (or rather the MBP with a M370X) is as cool as with the Iris Pro and thus the fan noise isn't any worse with dGPU rather than iGPU?

 

[yjchua95]

Yes, I read about that in another review, and it seems logical since you most likely can user more cooling with 2 separate chips compared with distance between then rather than stuck together. Do you have a feeling if this is true for non stress tests as well, that the M370X (or rather the MBP with a M370X) is as cool as with the Iris Pro and thus the fan noise isn't any worse with dGPU rather than iGPU?

It'll be as cool given that the M370X is disabled via gfxcardstatus. Fan noise are identical if both are doing intensive tasks.