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Mobile G-SYNC Confirmed and Tested With Leaked Driver
jones_supa writes: A few weeks ago, an ASUS Nordic support representative inadvertently made available an interim build of the NVIDIA graphics driver. This was a mobile driver build (version 346.87) focused at ASUS G751 line of laptops. The driver was pulled shortly, but PC Perspective managed to get their hands on a copy of it, and installed it on a ASUS G751 review unit. To everyone's surprise, a 'G-SYNC display connected' system tray notification appeared. It turned out to actually be a functional NVIDIA G-SYNC setup on a laptop. PC Perspective found a 100Hz LCD panel inside, ran some tests, and also noted that G-SYNC is picky about the Tcon implementation of the LCD, which can lead to some glitches if not implemented minutely. NVIDIA confirmed that G-SYNC on mobile is coming in the near future, but the company wasn't able to yet discuss an official arrival date or technology specifics.
The original story goes like this:
1. Nvidia claims that it needs the expensive FPGA chip to make variable refresh rate on current range of monitors. Calls it G-sync, tech adds significant costs and nvidia takes additinal licensing fee from monitors that include the said FPGA board.
2. AMD finds the adaptivesync spec in current VESA spec for embedded displayport used in laptops. Gets VESA to add it to upcoming displayport 1.2a spec for desktop. This does mostly the same thing without needed FPGA board or additional costly licencing fee. Monitors with adaptivesync and same specs end up about 100USD cheaper than monitors with G-sync and same specs.
3. Nvidia openly states that it cannot make G-sync cards compatible with adaptivesync any time soon and that it will continue supporting G-sync. Many pundits wonder how long Nvidia could keep attempting this kind of vendor lock-in on monitors before ceding its position due to rather extreme price differential between G-sync and adaptivesync monitors.
4. Laptops use eDP (embedded displayport) to connect monitor to GPU card which already has adaptivesync in the spec.
5, Alpha driver for nvidia mobile GPU sufraces which is made to work with adaptivesync over eDP, which driver itself calls "G-sync".
Conclusion - Nvidia lied about its adaptation of adaptivesync and it now appears extremely likely that nvidia will be using adaptivesync in its future products and just call it "G-sync mobile" or something similar.
Displayport is trying to be several different things to several different people; but in this case 'adaptive sync' serves the purposes of both:
For power-sensitive situations, being able to modify the frame rate can reduce power consumption(especially if combined with 'panel self refresh', also part of the embedded displayport standard, which calls for the panel driver to have enough RAM to store the entire frame so that the display driver and DP link can be shut down entirely if a static image is being displayed, only needing to wake back up when the image needs to be changed.)
The other advantage(and the one that Nvidia would be shooting for) is that it allows you to avoid the 'tearing' you get if your GPU's frame rate differs from your panel's refresh rate and you end up with part of one frame and part of the next frame drawn on the panel at the same time. If you can change the panel refresh rate, you can ensure that it refreshes when, and only when, the GPU has a new frame ready(obviously, you can't push the panel above a certain refresh rate, even if the GPU is doing something simple and could spit out hundreds or thousands of FPS; but it's a lot easier to cap at X FPS than it is to ensure that the framerate never dips under heavy load.)