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

Discussion in 'MacBook Pro' started by improwise, Jun 19, 2015.

  1. improwise macrumors member

    Jun 19, 2015

    Being a Microsoft .NET developer I don't really have to think of what OS to use mainly but still my last 3 Notebooks have been MacBook Pros running Windows, simply because there just wasn't any real alternative. This year though I decided to get a "real PC" but 4 PC laptops later I've yet again came to the conclusion that the best PC laptop is a MacBook Pro 15" 2015.

    Normally, I would just get a version with everything maxed out no matter costs but this year I'm having some doubts, mainly with the choice of GPU (Graphics card). IF GPU Switching had worked fine under Windows it would have been a no brainer but as most of you probably know it doesn't. Which have me thinking of if I should get the one without the AMD GPU instead to get better battery times and would like to hear your opinions on skipping the AMD version if favor of just the non AMD version. This will be used mainly as a mobile workstation so I don't really plan to do any gaming on it, most GPU intensive stuff will probably be some movies and light Photoshopping.

    Now, a few questions:

    1. Whats you overall opinion on skipping the AMD version for my needs and just go with the non-AMD (Intel Iris Pro version)?
    2. What are the chances currently of getting a Windows installation that supports GPU switching? I know there are different "hacks" out there that is supposed to solve this, but it still seems kind of shaky (no offence to the developers)?
    3. I noticed there is a "GPU swtiching utility" available on GitHub (could have been CodePlex also) that is said to be able to support GPU switching even though it would require a restart each time. That would be fine by me if it worked. Anyone that have used that one (or would consider trying) and that can give on opinion of how well it works?
    4. Will the built in Intel Iris Pro GPU be able to handle an external 4K monitor with no problem (just office use and some movies) over mini-DisplayPort or HDMI?
    5. What are the chances that the upcoming Windows 10 will offer better support for GPU switching on Macs running Windows without the need for "hacks"? Anyone tried it using the preview versions?

    Feel free to comment on anything related that I should have asked for/mentioned but haven't :)

    Thank you.
  2. Samuelsan2001 macrumors 604

    Oct 24, 2013
    1. sounds like a 13 inch with the IRIS would be fine for your use case, the IRIS pro will be just great.

    2. It's windows there is bound to be some software out there to do this.

    3. Not used it.

    4. Yes with ease

    5. Well a quick ghoogle suggest that currently not only does it not support it with AMD on macs it doesn't support it with AMD on anything, at least not well.

    In short the iGPU should be fine for your uses and the dGPU may well be far more trouble than it's worth.
  3. dusk007 macrumors 68040


    Dec 5, 2009
    1. If gameing was you aim the MBP was a bad choice anyway. I would definitely advise against the AMD GPU. Get the iGPU only model. If you don't really just get a Windows notebook. Those have better Touchpads. The MBP touchpad under Windows is really worlds worse, there isn't even smooth scrolling. If you want performance a Windows notebook is better and if you want battery life it is definitely not adviseable to get the dGPU.
    2. I am not aware of any hacks. Where have you heard of those? I know some have tried activating the iGPU if just to get quick sync functionality. But everyone failed to my knowledge. If somebody managed they keep the knowledge to themself.
    3. If you are talking about gfxCardStatus. That does absolutely nothing for Windows. It only works in OSX. No amount of restarting helps anything with Windows.
    4. It generally has plenty of ROP performance. A lot of pixels aren't a problem.
    5. All Windows offers plenty of support for GPU switching. The problem is that Apple deactivated the iGPU on UEFI level. Windows never gets any knowledge of the existence of the iGPU, it simply has no access. It would require some uefi hack to get it working. Once that is done simply installing an optimus or ads driver will do the trick, at least as long as only one monitor is in use.
  4. dusk007 macrumors 68040


    Dec 5, 2009
    Where you talking about this?
    I was not aware of that. I will try it out. I would be glad to be able to finally use handbrake with quick sync.
  5. maflynn Moderator


    Staff Member

    May 3, 2009
    1. For non gamers I think going the iGPU route is a no brainer, the Iris Pro is a powerful gpu.
    2. 0 chance
    3. Never heard of it, I guess you can try it at your own risk
    4. Yes
    5. No chance, MS is not looking to have windows run better on a 15" MBP with dual GPUs, they have much bigger fish to fry then to cater to a subset of a tiny percentage of computers running windows.
  6. improwise, Jun 19, 2015
    Last edited: Jun 19, 2015

    improwise thread starter macrumors member

    Jun 19, 2015
    Thanks for all replies, much appreciated.

    1. Seems like the Iris Pro is more than enough powerful to handle my needs. However, IF there would be a solutions for GPU swtiching on Windows, I don't really see what I would be loosing (except money :D) by getting a MBP with the AMD also.
    2. I'm referring to the the "UEFI installations" of Windows that seem to be possible. My understanding is that if doing that, the Windows installation would be able to see both GPUs, right? That said, this is not something I've tried and I don't know how well it works (if it works at all)
    3. I'm referring to this one. Please note that there seem to be a Windows version as well of this software. If it works as advertised, that would be great.
    4. Seems like the Iris Pro is fine.
    5. I'm not talking about Windows 10 making any special adjustments for "Macs running Windows" but rather related to point (2) above, if it would simplify matters of installing Windows in such a matter that it can access both GPUs.
    Regarding "getting a real PC instead". Believe me, I've tried. So far I've tried the Dell XPS13 2015, the Asus UX501, the MSI GS70 and the Aorus X7 Pro v3 (well, this one really is more for the gaming department and it is great at that). While they own have their strenghts, no one comes close to replacing my previous MBP 17" all in all. People complain about the MBP touch pad on Windows, well, in comparison to running OSX that is true, however the trackpad on my MBP 17" still easily beats all of the ones mentioned above even when running windows with standard bootcamp drivers. Only "real PC" I would still consider as alternatives to the MBP 15" 2015 is the Dell XPS15 (although Dell has horrible problems with quality, my XPS13 has been one nightmare after another) and the Lenovos which are great in many ways but a bit dull compared to the MBP.
  7. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    Not gonna happen. Apple uses a custom implementation of EFI, which incorporates all of UEFI 2.0 plus a little bit more custom to Apple. In Apple's case, if it detects that you're booting into Windows and there is a dGPU present, the UEFI will disable the iGPU completely and make it invisible to Windows. There isn't any way to get around it unless you know how to rewrite the UEFI.
  8. dusk007 macrumors 68040


    Dec 5, 2009
    You don't get a pixel by pixel scrolling experience like you have in osx in bootcamp. It is not as if Windows couldn't do that though. On the windows notebooks I tried that works fine. While the touchpad on the mbp is like a handicapped spastic with no abilities like multi touch or anything. And the trackpad++ driver is anything but problem free and does nothing for the mousewheel three lines at once scrolling.

    Windows 8 already installs just fine on UEFI without any BIOS emulation shananigans. But that changes nothing. Apple disables the GPU in the UEFI firmware. This switch-gpu program they say you have to hack the efi by installing a hack that tells the system set apple OS true. That OSX is actually running because it simply outright disables the iGPU otherwise.
    Apple does that on purpose and there is no easy way around. It has nothing to do with UEFI or Bios. They do it because they don't want to bother supplying a multiplex driver. And you get into troubles with external screens with the integrated GPU because that one isn't connected to the display out ports. Apple drivers know that and switch the dgpu on always when an external is connected. Windows standard drivers would just keep the external black and would look stupid. And Optimus drivers always use the display outs of the iGPU which means external displays simply would not work.

    I tried getting the iGPU to work in windows but have so far been unsuccessful. It is tricky. So far all I got was an unbootable OSX partition and some kernel panics. I fixed those and are live again but the only thing easy about it is to mess it up.

    I currently have the problem that I don't know how to copy the .efi extension file to /boot/custom on the EFI partition. I guess I need a new bootloader.
  9. improwise thread starter macrumors member

    Jun 19, 2015
    So, if one would go for a MacBook Pro without AMD but just the Iris Pro GPU, are there any other drawbacks (except lower for GPU intensive tasks of course)? And, if one goes for the one with the AMD, any idea of what you would loose with regards to battery time, heat etc?
  10. dusk007 macrumors 68040


    Dec 5, 2009
    I managed to boot the iGPU but never managed to get a picture. It stays mostly dark with only the wifi symbol blinking. There is obviously some driver conflict. Maybe it works with Linux but in Win 8.1 I could not get it to work.
    I can get a black picture and reboot again to boot with the 750M. It is not full black so the display output works but there is obviously something not loading correctly.
    I didn't break anything but that is about all the success I had. :(

    If you get the dGPU forget about every doing anything with the iGPU under Windows. I really only want it so I can have access to quick sync in Windows because there is no mac video converter that supports it and in Windows there is no Intel GPU.

    In Windows battery life of the MBP is anything between 2h and 4h. With the 750M that is. Again a discipline in which notebooks with good windows drivers will surpass it. Like a Samsung series 7. But they didn't update those afaik. They used to have great battery life. The Asus is a little on the weak side there.
    I just think usability in without a mouse is aweful under Windows on the MBP. It is great for gaming, plugged in with a mouse but touchpad and battery, I'd rather have a real windows notebook.
  11. improwise thread starter macrumors member

    Jun 19, 2015
    So GPU switching on Windows seems like no go then. Or is it your impression that it could be resolved with driver update? What are the actual differences with running Windows 8 on the MBP AMD vs the MBP non-AMD, in real numbers that is. How much hotter does it iget? How big is the difference in battery time? Anywhere you would notice the performance drop with the Iris Pro GPU if not gaming or running graphic intensive apps like games, 3D rendering etc?

    Trying to get an overall feeling what the actual differences would be, if it is something like 10-20% more heat and less battery it might be fine anyway, but if it is more than 50% it is not OK.
  12. dusk007 macrumors 68040


    Dec 5, 2009
    I think the GPU switching could be resolved with some more tinkering. I still might try disabling the 750M to maybe get the drivers to load correctly. When I have time to play around. In any case the solution is never optimal. From what I read in another thread on another forum people got both GPUs to be on but it does not shut them off properly to safe power, so in the end it would not be the same as graphics switching just access to iGPU features like quick sync.

    I guess you might get 30% more battery life with the Iris Pro only. I read reports from 30W vs 21W idle power consumption in Windows. But I don't know if the dGPU was fully turned of.
    Sadly Apple poorly optimizes Windows. There are lots of power saving features the hardware is capable of that are simply not turn on. I get about 4-6h on OSX with normal use but only 2-4 on Windows. That is almost half and the dGPU is not responsible. Even with the dGPU on I still get over 4h battery life in OSX. There are lots of small things that aren't activated. Performance is fine until it throttles but power saving is just not a thing.

    I cannot really test the performance difference but in what I read elsewhere the difference is no more than 30%. Which is usually not enough to really be noticeable. As in if something feels to slow on Iris Pro it likely would on a 750M too. The M370X is faster so the difference should be bigger. It is also known to be a little worse in idle power compared to nvidia.

    I will give the iGPU activation another shot in the next few days and report if I manage anything worthwhile.
  13. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    Not gonna happen mate.

    Apple uses a custom implementation of UEFI 2.0. If it detects that it's booting into Windows and the dGPU is present, the UEFI will disable the iGPU. And there isn't any way to get around that unless you can rewrite the UEFI and flash it. That isn't any small task.
  14. dusk007 macrumors 68040


    Dec 5, 2009
    there is an efi boot file called set_apple_os.efi I found which should tell the UEFI that you are actually booting an Apple OS even though you are booting something else and in effect keep it from disabling the iGPU.
    In theory it should or can work. Others apperantly managed. But I don't want to reinstall Windows or go too far out of my way to get it to work.
  15. improwise thread starter macrumors member

    Jun 19, 2015
    This is exactly what the GPU Switch utility mentioned above does, I looked into the source code. Not sure if it is working though, I guess different models/version have different firmware and not sure exactly how the utility tries to find the correct stuff to change.

    Dusk007, did you get the impression that there actually was a GPU switch and you were using the dGPU but then you run into other problems? Any difference if you boot Windows in safe mode with VGA enabled?
  16. improwise thread starter macrumors member

    Jun 19, 2015
    I've been running the MacBook Pro 17" from 2011 (or maybe 2012) in Windows a few years and would still say it's the best Windows experience all in all compared to other laptops, so perhaps running on the AMD version wouldn't be to bad after all.

    Dusk007, did you try to install Apples Iris Pro drivers? As there is a MacBook Pro without the AMD GPU, I would assume that such drivers exists as part of bootcamp, or if they use standard Microsoft/Intel drivers.
  17. xiwong macrumors member

    Dec 9, 2013
    I used to run Windows a lot on my 2012 cMBP, and I just have to say this is really not a good idea. You can get a much better experience elsewhere.

    For the GPU topic, its a draw. Apple has a proprietary method of graphics switching and will not provide Windows drivers for it, so no matter what MS does it will never happen (the hack also doesn't work for me, I've tried it plenty of times). The only benefit of having Iris Pro is that it may save some battery, but the battery life is going to be horrible anyway (due to drivers) that I don't believe it will be the difference between the MBP having "all workday" battery life or not.

    You just have to remember that running the MBP in Windows loses any advantages it could have (and I am not debating OS X vs Windows). The touchpad is quite bad, keyboard brightness still is finicky, display brightness is annoying to control because the difference between levels is inconsistent, the light sensors don't work, Thunderbolt drops the connection, battery life is horrible, and it runs even hotter/throttles even more. So you lose the MBPs main traits, which are its battery life/performance for its weight class. That being said, Wifi is rock solid and USB 3.0 drives don't disconnect randomly, so that is a plus over running in OSX.

    I have a UX501, and while it has a few flaws (not like the MBP doesn't), for $1500 I think it is very competitive to the MBP and runs Windows significantly better. The Boot Camp drivers are so poorly written it makes me believe Apple does this on purpose to make users continue to believe that Windows is horrible.
  18. dusk007 macrumors 68040


    Dec 5, 2009
    After about 50 restarts I think I figured a few things out.
    I am still absolutely clueless how to get Optimus working. Reinstalling the Nvidia driver does not help as it seems. The 750M is still active and waiting to be used.

    Well here is the fun part of how many hoops you have to jump to activate that damn IGPU.
    shutdown OSX
    start Windows normally
    use GPU-switch to switch to the integrated Mode
    -integrated mode completely kills any ability to use an external display,
    because you basically switch the display output in the muxer.
    go into Device Manager and disable the dGPU
    - screen goes black
    kill the notebook
    start in refint or any other bootmanager set_apple_OS.efi / takes about a split second then you are right back
    start Windows

    voila now you get the Intel Iris Pro and it works. Windows installs all drivers automatically, you don't have to do a thing. Still I downloaded the newest one. Gave Handbrake a shot. 1080p video to h264/high/level 5.0/best quality setting converts with 75-80 fps and the CPU does not even sweat (35W package load, 8W the CPU, 15W gpu). That is a lot faster than the software. I am not sure to which software level it is exactly equal to but there are four settings from fast to best quality and this was best quality so it should be equal to one of the slower software modes. It is definitely fast.

    Optimus: Didn't get it to work. No clue what to do about it. Both GPUs are there and enabled. :(
    I am guessing with enough tinkering you could get it to work somehow but I won't bother. That would take some work and I really only need it for handbrake overnight converting vids to archive.
    Battery life: Is horrific. Not doing much but playing around with settings and a little web surfing 2h15min is the estimate on a full charge. I did all the heavy duty stuff still plugged in so this is near idle load. Its abysmal.
    That is all on balanced power plan.

    Fazit you can get it to work but it is troublesome. And you need that complicated startup everytime. I tried just starting with setappleos directly without the whole procedure of setting integrated and disabling the 750M and always got a black screen.
    Somehow along with getting optimus to work it should be possible to set the Iris Pro as primary which I think is the problem. The notebook starts up but then tries to use the dGPU whose display output is not in use because it is switched to the other one in the muxer. I am sure there is a fix for it somewhere.
    I also tried plugging in an external screen and see what happens. There is a normal picture for a second as the 750M jumps to the rescue (it is obviously not off) but then everything is black. Removing the cable again returns the picture but now the touchpad driver said it hates live, I had to plug in a mouse. Ergo not adviseable to plug in a monitor it confuses the hell out of the hardware.

    Seriously a MBP is a great notebook under OSX but under Windows it makes a good desktop replacement but little more. Forget the dGPU model unless you want to use it the whole time. That is just not practical even if somewhat doable. Other real Windows notebooks actually use the hardware's power saving features and get decent battery life. Don't get a MBP for main Windows use unless you intend to use it mostly on a desk with mouse and plugged in anyway.

    FWIW when Windows 10 launches it will probably bring a flood of new notebooks on its back. Samsung will likely release an update within 2 months, Dell already announced the new slim bezel 15" and yeah the Asus UX501 is not great in battery life but it still beats the MBP under Windows use and it comes with a better touchpad, better cooling system, more powerful 960M GPU and an even higher def display for a lot less money if you forgo PCIe storage which is really overrated because it makes no difference in how speed the system feels.
  19. improwise thread starter macrumors member

    Jun 19, 2015
    Yes, I know the MBP on Windows has some limitations but despite that, I still haven't been able to find a better PC laptop for Windows. I actually owned the UX501 for a couple of week but, sorry to say, it felt like a cheap imitation of the MBP. For $US1500 however it could probably be a better value.
  20. improwise thread starter macrumors member

    Jun 19, 2015
    Dusk007, thank you very much for trying this out and reporting back on it, much appreciated. Will have to do some thinking on what to do here, I've really tried to get a "real" PC laptop this time but so far haven't found one that is better than the MBP despite it's flaws with Windows. Only 2 alternatives left that I can think of are the XPS15 (new version coming in a few months and Dells has well known QA probems) or the Lenovo T550 (great in many way but only a 2 core CPU).

    Any idea of what performance loss you get these days when running Windows as virtual using Parallells, VM or similar running on MacOS? How well does it work if you have no plans of gaming or similar? My main concern I can think of is sharing of CPU and RAM which you don't have to do with Bootcamp.
  21. improwise, Jun 20, 2015
    Last edited: Jun 20, 2015

    improwise thread starter macrumors member

    Jun 19, 2015
    A related question, what are the actual power requirements of the AMD GPU (M370X) compared to the Iris Pro? It seems like the M370X isn't exactly performance beast but I've also read that it might not be to bad when it comes to power consumption either. If this is true, the actual difference between it and running on the Iris Pro might not be that big after all

    Interesting from the NotebookCheck review:

    "We cannot confirm the advertised runtime of 9 hours, at least in our practical test. Our tests determine realistic runtimes of around 7 hours of wireless browsing or HD video playback if you adjust the display brightness to around 150 cd/m². Because of the higher power consumption, the battery will only last for less than 5 hours when you use Windows 8.1. Depending on the load you can realize much longer (idling OS X and minimum brightness: more than 17 hours) or much shorter runtimes (Unigine Heaven at the highest brightness: almost 2 hours). The 15-inch version cannot keep up with the stamina of the smaller MacBook Pro 13 Retina – but the results are more than impressive compared to the Windows competition."

    7 hours average on OSX and 5 hours on Windows actually isn't all that bad. In percentage that is of course a quite big difference, but in actual usage it might not be all that much. 5-7 hours is neither "I don't bother taking the charger with me" nor "I'm afraid to just unplug it". As a comparison, the Dell XPS15 (a "real" PC laptop) also lasted about 5 hours when tested by NotebookCheck, so a MBP 15" with M370X still offers similar battery runtimes as the XPS15.
  22. xiwong macrumors member

    Dec 9, 2013
    I have a M370X rMBP for work (previously had a 650m rMBP) and I would say the power requirements are more than the 750M, so battery life should be even worse with it stuck on. When this Cape Verde first came out in 2012, it was a class (both in power usage and performance) above the Kepler GK107. While improvements have obviously been made over the past few years, it is not enough for the MBP's power and thermal envelope.

    Notebook check says "Once we had noticed some occasional GPU throttling, it is hardly surprising that the losses in the stress test are even more dramatic. After our one-hour stress test with Prime95 and FurMark (Windows), the CPU runs at only 1.2 GHz, while the graphics card is also limited to just 400 MHz. Even though devices from Asus, Acer & Co. also throttle, none of the direct rivals loses that much performance." Under their gaming review, they note that stuttering was really bad as well (which boggles my mind on how it could get a 91% on gaming with such huge flaws). This is more throttling compared to the 750m, which means the M370X likely produces more heat and draws more energy.

    I was able to get around 5 hours of battery life with my 650m work rMBP with GPU switching off (cause of the nasty GPU reset bug that froze the computer). I also ran the M370X until it was confirmed the issue had been fixed, and I could not get above 4-4.5 hours with similar usage.
  23. dusk007, Jun 21, 2015
    Last edited: Jun 21, 2015

    dusk007 macrumors 68040


    Dec 5, 2009
    This might interest you.
    I got some info about what to do there.

    I think as far as dGPUs go the 750M is likely the most efficient of the bunch. You could get a refurb. Then again the 750M is such a small bit faster than the Iris Pro it is kind of pointless.

    Fusion is fine for office like work. CPU performance is not that far removed. GPU, well, you are better of with an Iris Pro native then with a M370X that runs in Parallels. DirectX to OpenGL to Apple drivers just isn't something that breaks records.
    I don't use Parallels because it was always too buggy for me. Fusion is a more stable even if they are a couple months behind in the newest features and performance improvements.
    VMs are quite usable today but they still don't feel like the native thing. It is not the missing RAM, Windows does not need that much to run well, especially not when there is an SSD. But responsiveness and fluidity of animations is just not the same.
    Try it out on which ever system you have now. Run a Linux distro in VM and natively for example. I think the results should translate.

    PS: How was the load noise of the Asus? From what i can tell it should be really quite nice. The MBP gets from quite okay at 5000rpm to 3 to 4 times louder at 6000rpm. If they managed to top out at 5000rpm and just grow the heatsinks the whole noise issue would be so much nicer under load.
    Really where the Asus messes up is by trying to keep temps below 85C if they'd just go to 99C like the MBP the results should be quite good.
  24. improwise thread starter macrumors member

    Jun 19, 2015
    Thanks for all the insightful answers. The absurdity seem to be that despite the MacBook Pros obvious shortcomings when running Windows I still haven't been able to find a "real" PC laptop that is better then the MBP of running Windows. Or rather, they all seem to have other problems that makes them feel kind of rubish in compressions. Like the XPS13 I'm now typing on, which I'm more and more frustrated with every day. Yes, light and thin but also plastic in comparison with MBP and with horrible quality problems with keyboard, screen etc. Will now require second service run in less than a month.

    Noise on the UX501 was ok, didn't really notice it much unless heavy load. But in other regards it simply can not match the MBP or Asus advertisement. Display can't show yellow correctly, speakers are a joke, keyboard is ok but not even close to the one on MacBook Pro. Of course, count in price and it might offer better value but disregard that and I don't hesitate to say that I still prefer the MBP 17" from 2011/2012 to that (which is returned now).
  25. improwise thread starter macrumors member

    Jun 19, 2015
    Is this running MacOS or Windows?

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