We’ve already seen Nvidia’s G-Sync in the headlines this morning, but the company has also been working on implementing G-Sync for their mobile GPUs that go into notebooks. Nvidia intends for G-Sync in the mobile space to remain a “gaming” feature, and as such we’ll never see this sort of thing in low-end notebooks in the future. G-Sync on the desktop is a pretty important development for graphics technology in games and suitable applications, but G-Sync and variable refresh rate technology in general in the mobile space is a game-changer (Ding! Roll credits). Click that button to read more words.
Just a refresher, before we learn more about what’s happening here. Typically, in desktop monitors, Nvidia sells their G-Sync scaler to the monitor manufacturer who wants to implement it for gaming purposes. Nvidia sits down with these companies and recommends what sort of display they need to look for, one that has been pre-tested and verified to be compatible with the G-Sync module. They then test and validate the prototypes before the monitors get sent into production and do any necessary tuning to the display to ensure that the variable refresh rate (VRR) experience remains of the same high standard that Nvidia sets for other G-Sync monitors.
Once validated, the monitor vendors can use G-Sync branding on their product boxes and can be listed by Nvidia as having compatible products with G-Sync. The key here is not only being a technology enabler, but that Nvidia also does some direct marketing to their fans in the process as well. Having the world’s largest graphics vendor in the discrete market validate and support your product is a huge boost for your brand, which is why the G-Sync rollout is mostly limited to high-end stuff, and tends to have a big marketing push behind it.
G-Sync for mobile follows a different path than it does for the desktop. There’s no place for the G-Sync module and it would consume too much power and product too much heat. Laptop monitors are also commonly driven directly by the graphics card in use through a connection like LVDS or embedeed Displayport, both of which are possible without a scaler. The graphics hard has to be carefully selected to be able to run the monitor properly, which is why you’ve probably run into the situation where the standard Intel, AMD or Nvidia drivers don’t work on the system properly, but the modified in-house ones do – this is one of the reasons why. Not only does the panel have to be compatible electrically using a connector that the GPU can also interface with, the drivers need to be tuned accordingly to ensure that the user experience is good.
So in this instance, Nvidia works with the notebook manufacturers who approach them to implement G-Sync on supporting hardware. Nvidia will tell them which notebook panels are suitable for the purpose and what size VRR window to aim for (say, 30Hz to 75Hz), and will go through the trouble of validating multiple displays to find the right one. Because Nvidia has had a hand in selecting the right display, which may or may not include a scaler, they can tweak their G-Sync drivers and tune the panel’s software to support it properly, giving it most of the benefits of VRR, but without that expensive module in place. In practice, this is exactly the kind of thing AMD is doing with Project FreeSync, but AMD is doing it on a much wider scale on the desktop.
That brings up some interesting questions, like “Does G-Sync still work for external displays?” and the answer is yes. The other one is “Will my notebook’s display be supported?” and that answer is less clear-cut – unless you’re running a Maxwell-based mobile GPU from the GTX 960M and upwards, you’re probably not getting in on this action. However, despite Nvidia having a hand in making these “gamer grade displays” available to notebook manufacturers for their Maxwell parts, there’s every chance that an older Geforce-based notebook like the GTX 780M, is paired up with a eDP panel that might have VRR support unintentionally. That probably won’t happen to everyone, but there is a chance that this could happen.
A further question would be, “Is this mandatory?” and I’m sad to say that it may be moving in that direction. According to PC Perspective, their sources inside Nvidia claim that all GTX graphics cards on the mobile side will only be sold to notebook manufacturers if they agree to have it feature a G-Sync-capable display as well. Its a double-edged sword because on the one hand, they’re getting access to VRR and assistance with panel selection, but on the other it removes their freedom of choosing what they want their product to end up, possibly moving them over to AMD.
Additionally – and this is the case already for G-Sync-capable mobile GPUs connected to G-Sync desktop displays – the main requirement for this to work is that the display must be connected directly to the GPU itself. That leaves out the option of using Intel’s integrated graphics, or the Optimus switching engine which Nvidia has had for ages now. So, there’s no chance of switching off the big, burly GPU and moving to Intel’s much more power-efficient GPU if you want G-Sync to work. AMD’s mobile FreeSync, which will probably be announced sometime this year, will have to work around this as well, and it wouldn’t surprise me to see them fixing up Enduro and figuring out a method to make their GPUs as well as Intel’s function with a mobile FreeSync display without cutting one or the other out the picture.
Which notebooks will ship with G-Sync capability?
Currently, Nvidia has readied G-Sync for six notebooks at launch. All of these will feature G-Sync displays capable of up to 75Hz refresh rates and Geforce GTX-class graphics. You’ll notice that the GTX 960M is omitted here, and that’s because in the launch window for Maxwell, Nvidia rebranded a higher-clocked variant of the GTX 860M as a GTX 960M, which caused confusion for buyers because they thought they were getting a Maxwell part. Nvidia might skip the GTX 960M entirely for the purposes of completeness and a cleaner lineup, which would be unfortunate. Their lineup goes down as low as the GTX 950M, found in notebooks around the R12,000 mark, which would make for a killer combo with a 1080p IPS display.
Some of these notebooks have displays that can be overclocked, specifically the MSI GT72 G, which can apparently overclock all the way to 100Hz without skipping frames. If you want to really give the GPU a workout, overclocking the display might be of benefit to your fast-paced twitch shooters. Also, is is pretty cool that mobile G-Sync works with SLI systems already, but Nvidia has had almost two years to get this right, so it is nice to see them not resting on their laurels.
Of course, mobile G-Sync works with all the new features announced in today’s G-Sync update for the desktop (sans the ability to run ULMB) and if you already have a notebook with a Maxwell-based GTX-class GPU in it, download the latest Geforce 353.06 drivers and see what they do for you. Who knows – you might end up having a supported G-Sync display already!