Nvidia G-Sync

G-Sync is a proprietary adaptive sync technology developed by Nvidia aimed primarily at eliminating screen tearing and the need for software alternatives such as Vsync.^[1] G-Sync eliminates screen tearing by allowing a video display to adapt to the frame rate of the outputting device (graphics card/integrated graphics) rather than the outputting device adapting to the display, which could traditionally be refreshed halfway through the process of a frame being output by the device, resulting in screen tearing, or two or more frames being shown at once.^[2] In order for a device to use G-Sync, it must contain a proprietary G-Sync module sold by Nvidia. AMD (Advanced Micro Devices) has released a similar technology for displays, called FreeSync, which has the same function as G-Sync yet is royalty-free.

NVIDIA built a special collision avoidance feature to avoid the eventuality of a new frame being ready while a duplicate is being drawn on screen (something that could generate lag and/or stutter) in which case the module anticipates the refresh and waits for the next frame to be completed.^[3] Overdriving pixels also becomes tricky in a non-fixed refresh scenario and solutions predicting when the next refresh is going to happen and accordingly adjusting the overdrive value must be implemented and tuned for each panel in order to avoid ghosting.^[4]

Hardware

The module carries all the functional parts. It is based around an Altera Arria V GX family FPGA featuring 156K logic elements, 396 DSP blocks and 67 LVDS channels. It's produced on the TSMC 28LP process and paired with three DDR3L DRAM chips to attain a certain bandwidth, for an aggregate 768MB capacity. The employed FPGA also features a LVDS interface to drive the monitor panel. It's meant to replace common scalers and be easily integrated by monitor manufacturers, who only have to take care of the power delivery circuit board and input connections.

GPU and system requirements

• GPU: G-SYNC features require an Nvidia GeForce GTX 650 Ti Boost GPU or higher.
• DRIVER: R340.52 or higher.
• Operating System: Windows 7, 8, 8.1 and 10. Linux, FreeBSD, Solaris.^[5]
• System Requirement: Must support DisplayPort 1.2 directly from the GPU.

^[6]

Criticism

G-Sync faces some criticism due to its proprietary nature, and the fact that it's still being promoted when free alternatives exist, such as the VESA standard Adaptive-Sync which is an optional feature of DisplayPort version 1.2a.^[7] While AMD's FreeSync relies on the above-mentioned optional component of DisplayPort 1.2a, G-Sync requires an Nvidia-made module in place of the usual scaler in the display in order for it to function properly with select Nvidia GeForce graphics cards, such as the ones from the Kepler microarchitecture (GTX 650Ti and later).

List of G-Sync-enabled monitors

^[8]

List of upcoming G-Sync-enabled monitors

List of G-Sync enabled GPUs

^[9]

G-Sync Notebook

Nvidia announced that G-sync will be available to notebook manufacturers and that in this case, it would not require a special module since the GPU is directly connected to the display without a scaler in between. According to Nvidia, fine tuning is still possible given the fact that all notebooks of the same model will have the same LCD panel, variable overdrive will be calculated by a shader running on the GPU, and a form of frame collision avoidance will also be implemented.^[4]

Big Format Gaming Displays

At CES 2018 Nvidia announced a line of large gaming monitors built by HP, Asus and Acer with 65 inch panels, 4k, HDR, as well as G-sync support. The inclusion of G-sync modules make the monitors among the first TV-sized displays to feature variable refresh-rates.^[10]

See also

• Variable refresh rate
• FreeSync
• Refresh rate

References

External links

• G-sync Monitors
• Video: How G-SYNC Works
• Nvidia G-Sync overview