The Surface Book's Nvidia GPU is reportedly a GTX 940M

By Scorpus
Oct 20, 2015
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  1. When Microsoft announced the Surface Book two weeks ago, the optional discrete Nvidia GPU integrated into the keyboard base drew some attention. Microsoft didn't provide exact specifications for this GPU, but promised it would improve the graphics performance of the device, especially in 3D modelling workloads.

    The lack of information made the Surface Book's GPU a bit of an intriguing mystery. Wanting to figure out exactly what was in the hybrid device, a few users have checked the Nvidia Control Panel and ran GPU-Z on demo units in Microsoft's retail stores, discovering some GPU specifications that aren't too surprising.

    The findings have revealed a GPU with 384 CUDA cores, 16 ROPs, 32 TMUs, and a base clock of 954 MHz that can boost up to 993 MHz. On the memory front we're looking at 1 GB of GDDR5 on a 64-bit bus, providing 40.08 GB/s of bandwidth.

    The specifications indicate that the GPU inside the Surface Book is a slightly underclocked variant of Nvidia's GeForce GTX 940M. This means we're looking at a GM108 core inside the Book, built on a 28nm process with a 33W TDP.

    On paper, the GTX 940M in the keyboard base should deliver more than double the GPU performance of the 15W Skylake-U processor found in the Surface Book's tablet component. This is a pretty decent boost in GPU performance for a device that can be used as both a tablet and a laptop.

    Microsoft also expects the GPU to provide 2x the performance of the "best available" 13-inch MacBook Pro, which features a 28W Broadwell processor with Intel Iris Graphics 6100. In practice the GTX 940M should outperform Intel's integrated graphics solution, but on paper Microsoft might be slightly overstating the performance of the Surface Book's GPU.

    Permalink to story.

  2. Arris

    Arris TS Evangelist Posts: 4,588   +278

    Hmmm, sounds good. But good luck playing any games on it at the native 3000x2000 resolution with any higher graphical detail settings.
    Darth Shiv likes this.
  3. Soulburn74

    Soulburn74 TS Rookie

    Definitely higher end then intel onboard, however as discrete gpu's go (even for mobile chipsets), its on the low end.....
    Darth Shiv likes this.
  4. Soulburn74

    Soulburn74 TS Rookie

    For the same amount of money spent on a decked out Surface book, one could step up to a fully fledged gaming laptop (Such as MSI GT72, with 980M, or soon the 980), obviously you are no longer in a tablet/convertable/great battery life machine.........guess it really depends on what you really want.......
    Reehahs likes this.
  5. Teko03

    Teko03 TS Maniac Posts: 302   +104

    It doesn't depend on what you really want, it depends on how you'll be using this machine. A full fledged gaming laptop is never mobile --- the model you mentioned is 8.4 lbs and packs a 17-inch 1920x1080 screen. The Surface Book is more than half that, with a 13.5-inch 3,000x2,000 screen. Really, if you're buying a Surface Book, I'd hope gaming isn't #1 on the priority list. Instead, mobility, application development, photo editing, some video rendering & AutoCAD should be at the top of your "needs".
    cliffordcooley and spectrenad like this.
  6. Skidmarksdeluxe

    Skidmarksdeluxe TS Evangelist Posts: 6,340   +1,938

    I really like these things. It's a good thing I don't need or require one otherwise I could find myself wasting money.
  7. Nobina

    Nobina TS Evangelist Posts: 807   +270

    It's a nice add, I can see it playing less demanding games like LoL, CSGO and Dota which is really nice. Downside to me is that it will probably generate more heat and consume more power.
  8. AvalonMD

    AvalonMD TS Enthusiast Posts: 36   +42

    If I recall, DirectX 12 should allow for GPU's from multiple vendors to work together. If that's true, then shouldn't the Intel GPU in the Screen work together with the nVidia in the base when docked thereby further improving the "specs" mentioned on paper?
  9. Kibaruk

    Kibaruk TechSpot Paladin Posts: 2,422   +470

    Was disapointed with the specs, hoped for something more on par with pricing and oomph of the book.

    I'm pretty sure no one will buy one of these to do hardcore gamming.

    This is too many ifs together in a single post :p
    Arris and AvalonMD like this.
  10. spectrenad

    spectrenad TS Rookie Posts: 97   +18

    Ohhh I wanna hear more on that, can someone confirm this? :eek:
  11. Arris

    Arris TS Evangelist Posts: 4,588   +278

    True, but then what do non gamer types need the GTX940M for in the first place then? If it's productivity focused should be a Quadro or just be done with the intel HD/Iris whatever graphics :p
  12. bazz2004

    bazz2004 TS Evangelist Posts: 1,213   +200

    I think that the new ideas are excellent. The defective nVidia m8400/8600GT range of graphics chips were used in huge numbers and caused uproar lasting for several years. Replacing a graphics chip integrated on the motherboard is not cheap or easy so anything that puts the graphics chip elsewhere is a big advantage. eBay is full of duff laptops with failed graphics chips fit only for landfill. Microsoft are pushing laptop design forward at last so well done to them.

    The prices are well beyond what I'd feel happy paying but as other makers come out with new products that will gradually change. At least I can now see some laptops that I'd like to own.
    Last edited: Oct 21, 2015
  13. asdasdaf

    asdasdaf TS Rookie

    I don't see why you guys are excited about this. Even with Broadwell Intel Iris has been on par with a 940M, even better in some specific benches, yet manufacturers kept pairing CPUs with a worse IGP and a dedicated 940M. Worst idea ever.
    Lets hope (or actually ask for it) that the manufacturers and Intel come up with more sense this time around.
  14. Mandark57

    Mandark57 TS Rookie Posts: 19

    I want one so bad. That would be a little app development machine, and my remote work machine
  15. Evernessince

    Evernessince TS Evangelist Posts: 1,102   +532

    This is only for games that are programmed to do so. It won't be backwards compatible, won't work on regular applications, and most likely won't be supported by the majority of devs. I can tell you right now, there's no way Nvidia is going to let any of it's gameworks devs program that sort of functionality in.

    For the uninformed, VirtuMVP already does a thing similar to this. The result is often nothing. As it turns out, integrated graphics are often far to slow to be able to even help out discrete graphics cards.

    Read above.
    spectrenad likes this.
  16. Emexrulsier

    Emexrulsier TS Guru Posts: 503   +42

    The x40 series of cards is still a low end budget card and tbh they normally do run slower than comparable intel chips of the same age.
  17. Arris

    Arris TS Evangelist Posts: 4,588   +278

    Looking at's info on Iris 6100( and 940M( there doesn't seem to be a massive performance difference. I got confused by Nvidia's terrible naming convention that makes you think a mobile version is comparable to a desktop card of the same series. I shouldn't have(as I'm aware of my old laptop's 680M being the equivalent of a desktop 580) but I did. Unless this will be available with a choice of higher spec discrete graphics cards it does seem rather underwhelming.
  18. dipique

    dipique TS Rookie

    For me, having 1gb of dedicated gddr5 memory (unlike the gddr3 memory in the standard 940m) is pretty compelling.
  19. asdasdaf

    asdasdaf TS Rookie

    You remind me of those people that only compare GPUs by their memory size...

    If MS used dual-channel DDR3-2133 for system memory (I don't know what they actually use), that's 34GB/s, not much worse than the 40 quoted for the GPU. But even with DDR3-1600 I'd say for most situations the processing speed is more limiting than the memory speed.

    In the end, it is the benchmarks and game tests that matter, and in them I expect Skylake Iris to beat the 940M considering how Broadwell Iris matched up with it. We should hopefully see some actual numbers soon.

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