Two companies are about to release technologies that outright replace the use of V-SYNC: NVIDIA’s Fast Sync and AMD’s Enhanced Sync. These technologies were created with an eye towards VRR (Variable Refresh Rate), allowing compatible monitors to refresh at whatever rate they’re capable of, rather than being limited by arbitrary refresh rates set in firmware (30, 60, 120Hz for example). Fast Sync already exists in a few titles, but it has been limited to internal beta testing so far. In this article, we will briefly explain how both work and which games have support at the time of writing this article.
Fast Sync explained
Unlike V-SYNC, Fast Sync does not actually pause the game when the monitor is refreshing at a rate slower than the GPU can render. Instead, frames are displayed as soon as they’re available from the rendering pipeline. In other words, it skips drawing some of those frames that would have been duplicated but don’t violate the signal’s integrity by introducing tearing or judder. The net result is a significant reduction in input latency and no need to use V-SYNC.
However, as the name implies, it’s fast but not quite as smooth as using V-SYNC would be; those extra frames that weren’t drawn still take time to produce and Fast Sync doesn’t wait for them before displaying newly rendered ones as V-SYNC does. So while Fast Sync doesn’t suffer from V-SYNC’s input lag, there is still some additional latency compared to using V-SYNC on a traditional 60Hz display.
AMD Enhanced Sync explained
AMD’s Enhanced Sync works similarly to NVIDIA’s solution, except that it has the added benefit of being able to dynamically adjust its behavior based on the frame rate. If the graphics card isn’t pushing out frames quickly enough for the monitor to keep up without dropping any, Enhanced Sync will behave like regular v-sync and wait for new frames. Once things are going faster again, it will skip drawing duplicate frames as NVIDIA’s Fast Sync does.
Enhanced Sync was first implemented in Ubisoft’s Far Cry 5, released March 27, 2018.
NVIDIA Fast Sync Vs enabling V-SYNC in games
As mentioned earlier, NVIDIA’s Fast Sync exists already but has been kept under wraps until now for unknown reasons. It works very similarly to Enhanced Sync, with the added benefit of being able to dynamically switch refresh rates without having to rely on game support. That said, there are some limitations that come with using it:
Monitors must have a minimum response time of 1ms GTG (grey-to-grey), which rules out all current G-SYNC monitors as well as 120Hz TN displays. Furthermore, you will have to use the Windows desktop resolution scaling feature so your monitor can double or triple its apparent pixel count and achieve 96 – 144Hz operation. This will introduce additional input lag, but if your hardware is capable of consistently hitting that high of a frame rate then you can benefit from reduced input latency compared to using G-SYNC or V-SYNC.
NVIDIA’s Fast Sync and AMD Enhanced Sync both work with the following titles: Far Cry 5 (AMD Enhanced Sync) Apex Legends (frame limiter only, no support for variable refresh) Battlefield V (Fast Sync): enables in fullscreen and windowed modes, triple buffering must be off Fallout 76 (Fast Sync): enable via .ini file as explained here Rage 2 (Fast Sync) Metro Exodus (Enhanced sync with r_vsync 0 command-line argument) Resident Evil 2 Remake (Fast Sync) Shadow of the Tomb Raider (Enhanced sync with Launch options: +restart 1 + “‘stxg2gsync 0 / sys_ssr 0”) Sid Meier’s Civilization VI (Fast Sync) Star Control: Origins (Enhanced sync with in-game vsync option) Warhammer Vermintide 2 (AMD Enhanced sync, Fast Sync)
Both AMD and NVIDIA are working on bringing Adaptive-Sync to other titles as well. The following is a list of upcoming games that will have variable refresh rate support via either G-SYNC or FreeSync at some point in the future after their respective launches: Cyberpunk 2077 Elder Scrolls Online Gears 5 Just Cause 4 Metro Exodus System Shock Remake Wasteland 3
AMD is working with the following developers to implement Enhanced Sync support: Ubisoft (Far Cry 5) Bethesda Game Studios ( Fallout 76, The Elder Scrolls VI)
Lastly, it’s important to note that Fast Sync should work fine on any G-SYNC or FreeSync monitor. It just may not be as beneficial as using G-SYNC if your hardware isn’t consistently hitting above the monitor’s minimum refresh rate.