What Is G-SYNC And What Does It Do?

G-SYNC synchronizes refresh rates of a monitor (Hz) to the frame rates of a GPU (FPS) in order to eliminate screen tearing and stuttering.

Answer:

Gaming monitors with NVIDIA’s G-SYNC technology feature a dedicated module that provides a variable refresh rate for tear-free gameplay with compatible graphics cards.

Wondering what a G-SYNC monitor is and how it’s different from G-SYNC Compatible, G-SYNC Ultimate, or FreeSync displays? You’ve come to the right place!

What Is G-SYNC?

G-SYNC is a special chip installed inside a G-SYNC monitor that provides you with a variable refresh rate (VRR) and variable overdrive if you have a compatible graphics card.

There are three generations of G-SYNC modules:

  • v1 module with DisplayPort 1.2
  • v1 module with DisplayPort 1.2 and HDMI 1.4
  • v2 module with DisplayPort 1.4, HDMI 2.0, and a cooling fan (some newer modules may feature two HDMI 2.0 ports)
NVIDIA G-SYNC Module

How Does G-SYNC Work?

G-SYNC allows your monitor’s refresh rate (Hz) to change dynamically, according to your GPU’s frame rate (FPS). As a result, all screen tearing is eliminated up to the monitor’s maximum refresh rate at no noticeable input lag penalty (~1ms).

So, if you have a 144Hz gaming monitor and you have 60FPS in a game, G-SYNC will dynamically change the display’s refresh rate to 60Hz in order to provide you with 60 whole frames per second without tearing.

Meanwhile, variable overdrive will ensure that the pixel response time speed is adjusted accordingly thus preventing pixel overshoot at low frame rates and ghosting at high FPS.

Another advantage of the G-SYNC module is that it replaces the regular scaler in the monitor, so you’ll have lower input lag.

The main disadvantage is the price, as well as limited connectivity options since G-SYNC modules don’t have VGA, DVI, or USB-C (for DP Alt Mode) ports.

G-SYNC vs FreeSync & G-SYNC Compatible

what is g-sync

Unlike G-SYNC, FreeSync and G-SYNC Compatible monitors don’t have dedicated modules.

Instead, they rely on VESA’s free and open-standard Adaptive-Sync protocols in DisplayPort and/or HDMI connectors for variable refresh rate.

A G-SYNC Compatible monitor is essentially a FreeSync or ‘Adaptive-Sync’ monitor that’s been validated by NVIDIA to work without any issues when using their compatible cards.

So, what exactly makes G-SYNC special?

To start with, G-SYNC monitors usually have a wider VRR range than FreeSync and G-SYNC Compatible displays.

For instance, a 144Hz G-SYNC gaming monitor has a VRR range of 30-144Hz, whereas a similar FreeSync monitor will usually have a dynamic range of 48-144Hz.

So, if your frame rate were to drop to 40FPS, a G-SYNC monitor would change its refresh rate to 40Hz, while a FreeSync monitor would have to resort to LFC (Low Framerate Compensation) and multiply its refresh rate to 120Hz (40FPS x 3) in order to prevent tearing.

However, triggering LFC causes minor stuttering, so the overall gaming experience will be more pleasant on a G-SYNC monitor in this case.

As previously mentioned, since the G-SYNC module replaces the regular scaler of the monitor, G-SYNC monitors have lower input lag, though most FreeSync monitors have imperceptibly low input lag anyway.

The upsides of not having a G-SYNC module include lower price tag and more extensive connectivity options.

So, is G-SYNC worth it?

Well, it depends on the monitor and its FreeSync/G-SYNC Compatible counterpart, if it exists.

Sometimes, a FreeSync monitor will have just as wide VRR range as G-SYNC, and even though it may not have variable overdrive, its overdrive implementation can be very good nonetheless.

We have a dedicated article where we compare popular G-SYNC monitors to their FreeSync counterparts, as well as the best G-SYNC monitor buyer’s guide, which consists of all G-SYNC gaming monitors worth considering.

G-SYNC Ultimate

Gaming monitors with the G-SYNC Ultimate certification also feature a dedicated module, but with added HDR (High Dynamic Range) support.

The criteria for this certification has changed over the time, however.

Here are the old requirements:

G SYNC Ultimate Old Requirements

And here you can see the current requirements for G-SYNC Ultimate:

G SYNC Ultimate Requirements

So, the very first G-SYNC Ultimate gaming monitors, such as the Acer X35 and the ASUS PG27UQ, offered a next-level HDR viewing experience thanks to their high 1000-nit peak brightness and multi-zone backlight (with full-array local dimming).

Nowadays, you can see G-SYNC Ultimate monitors with a lower 600-nit peak brightness and inferior multi-zone backlights, down to 32 edge-lit local dimming zones, for instance, from something like the 512-zone FALD solution of the Acer X35.

These monitors still offer decent HDR image quality, usually with VESA’s DisplayHDR 600 certification.

You get noticeably better HDR image quality in comparison to SDR or DisplayHDR 400, but you’re not getting the ‘true’ HDR viewing experience, more like a glimpse of it. Some scenes will look a lot better, others might even look worse than SDR.

In other words, G-SYNC Ultimate no longer guarantees an amazing HDR image quality. It’s as misleading as other HDR certifications.

For the best HDR image quality, you’ll have to check if the monitor has a good full-array local dimming solution with many zones (or simply an OLED panel) among its specifications.

Note that G-SYNC Ultimate was previously branded as ‘G-SYNC HDR.’

G-SYNC Requirements

In order to use G-SYNC, you will need a G-SYNC monitor and a compatible NVIDIA graphics card (GTX 650 Ti Boost or newer) connected via DisplayPort.

Now, newer G-SYNC monitors, such as the Dell AW2721D, the LG 38GL950G, and the Acer XB273X also allow G-SYNC to be used with AMD graphics cards over DisplayPort, and also offer HDMI-VRR for consoles.

For G-SYNC Ultimate, you’ll need a GTX 1050 or newer graphics card with DisplayPort 1.4.

You can use our G-SYNC monitor list to find all G-SYNC and G-SYNC Ultimate monitors available.

All monitors certified by NVIDIA as ‘G-SYNC Compatible’ can be found in the list at the bottom of the article.

ULMB & Reflex Analyzer

Some (not all) G-SYNC monitors are also paired with NVIDIA’s ULMB (Ultra Low Motion Blur) technology, which uses backlight strobing to reduce perceived motion blur at a cost of picture brightness.

Note that ULMB and G-SYNC can’t be active at the same time – unlike some other MBR (Motion Blur Reduction) implementations, such as ELMB-Sync by ASUS or Aim Stabilizer Sync by Gigabyte, which allow for simultaneous backlight strobing and VRR (FreeSync or G-SYNC Compatible) performance.

Further, several new G-SYNC monitors feature the new NVIDIA Reflex Analyzer tool, which allows you to measure the latency between the supported monitor and a compatible mouse.

Compatible NVIDIA Reflex Analyzer monitors:

  • Acer Predator X34S
  • Acer Predator XB273U NX
  • AOG AGON PRO AG274QG
  • ASUS ROG Swift PG279QM
  • ASUS ROG Swift PG259QNR
  • AOC AGON PRO AG254FG
  • MSI Oculux NXG253R
  • Acer Predator X25
  • Dell Alienware AW2521H

Compatible NVIDIA Reflex Analyzer mice (click to enlarge):

NVIDIA Reflex Analyzer Supported Mice

Finally, keep in mind that NVIDIA Reflex Analyzer and NVIDIA Reflex are two different things.

NVIDIA Reflex doesn’t measure input lag, but rather reduces it in supported games.

To take advantage of it, you’ll need an NVIDIA GTX 900-series or newer graphics card and to enable the Reflex option in the settings of a compatible game, which includes:

  • Fortnite
  • Valorant
  • Apex Legends
  • Call of Duty: Black Ops Cold War
  • Call of Duty: Modern Warfare
  • Call of Duty: Warzone
  • Destiny 2

List of G-SYNC Compatible FreeSync Monitors

MonitorSizePanelResolutionRefresh RateVRR Range
Acer XV273K27”IPS3840x2160120Hz48-120Hz
AOC AGON AG241QX24”TN2560x1440144Hz30-144Hz
ASUS MG278Q27”TN2560x1440144Hz40-144Hz
Acer XG270HU27”TN2560x1440144Hz40-144Hz
Acer XZ321Q32”VA1920x1080144Hz48-144Hz
ASUS XG24824”TN1920x1080240Hz48-240Hz
BenQ XL274027”TN1920x1080240Hz48-240Hz
Acer XFA24024”TN1920x1080144Hz48-144Hz
AOC G2590FX25”TN1920x1080146Hz30-146Hz
ASUS VG278Q27”TN1920x1080144Hz40-144Hz
ASUS XG25825”TN1920x1080240Hz48-240Hz
ASUS VG258Q25”TN1920x1080144Hz40-144Hz
Acer ED273A27”VA1920x1080144Hz48-144Hz
Acer XF250Q24.5”TN1920x1080240Hz48-240Hz
BenQ XL254024.5”TN1920x1080240Hz48-240Hz
ASUS VG248QG24”TN1920x1080165Hz40-165Hz
ASUS VG258QR24.5”TN1920x1080165Hz40-165Hz
ASUS VG278QR27”TN1920x1080165Hz40-165Hz
Acer KG271 Bbmiipx27”TN1920x1080240Hz48-240Hz
Acer XF240H Bmjdpr24”TN1920x1080144Hz48-144Hz
Acer XF270H Bbmiiprx27”TN1920x1080144Hz48-144Hz
AOPEN 27HC1R Pbidpx27”VA1920x1080144Hz48-144Hz
Gigabyte AD27QD27”IPS2560x1440144Hz48-144Hz
LG 27GK750F27”TN1920x1080240Hz48-240Hz
LG 27GL85027”IPS2560x1440144Hz48-144Hz
HP 25x24.5”TN1920x1080144Hz48-144Hz
AOC G2590PX24.5”TN1920x1080144Hz30-144Hz
Dell S2419HGF24”TN1920x1080120Hz48-120Hz
HP 24x24”TN1920x1080144Hz48-144Hz
HP 25mx25”TN1920x1080144Hz48-144Hz
HP Omen X 25F25”TN1920x1080240Hz48-240Hz
LG 34GL75034”IPS2560x1080144Hz50-144Hz
Samsung C27RG527”VA1920x1080240Hz48-240Hz
AOC AG272FCX627"VA1920x1080165Hz48-165Hz
AOC AG272FG3R27"VA1920x1080165Hz48-165Hz
ASUS VG27AQ27"IPS2560x1440144Hz48-144Hz
Acer CP3721K P32"IPS3840x2160120Hz48-120Hz
Acer XB273K GP27"IPS3840x2160120Hz48-120Hz
Acer CG437K P43"VA3840x2160120Hz48-120Hz
Acer VG252Q P25"IPS1920x1080144Hz48-144Hz
LG 27GL63T27"IPS1920x1080144Hz48-144Hz
LG 27GL65027"IPS1920x1080144Hz48-144Hz
LG 27GN75027"IPS1920x1080240Hz48-240Hz
Gigabyte FI27Q27"IPS2560x1440144Hz48-144Hz
Gigabyte FI27Q-P27"IPS2560x1440165Hz48-165Hz
Acer XV273 X27"IPS1920x1080240Hz48-240Hz
LG 2019 OLED B9, C9, E955", 65", 77"OLED3840x2160120Hz40-120Hz
(HDMI 2.1)
LG 2020 OLED BX, CX, GX48", 55",
65", 77"
OLED3840x2160120Hz40-120Hz
(HDMI 2.1)
LG 2021 OLED B1, C1, G148", 55",
65", 77", 83"
OLED3840x2160120Hz40-120Hz
(HDMI 2.1)
LG OLED Z9, ZX, Z177", 88"OLED7680x4320120Hz40-120Hz
(HDMI 2.1)
Razer Raptor 2727"IPS2560x1440165Hz165Hz
Acer VG272U P27"IPS2560x1440144Hz48-144Hz
Acer VG272X27"IPS1920x1080240Hz48-240Hz
Dell Alienware AW2720HF27"IPS1920x1080240Hz48-240Hz
Lenovo Y27Q-2027"IPS2560x1440165Hz48-165Hz
ASUS XG279Q27"IPS2560x1440165Hz48-165Hz
AOC 27G227"IPS1920x1080144Hz48-144Hz
Acer XB273U27"IPS2560x1440165Hz48-165Hz
Acer XV273U27"IPS2560x1440165Hz48-165Hz
ASUS VG259Q24.5”IPS1920x1080144Hz48-144Hz
MSI MAG251RX24.5"IPS1920x1080240Hz48-240Hz
ViewSonic XG27027"IPS1920x1080240Hz48-240Hz
Acer XV272U P27"IPS2560x1440144Hz48-144Hz
Dell AW5520QF55"OLED3840x2160120Hz48-120Hz
LG 38GN95038"IPS3840x160048-160Hz48-160Hz
LG 38WN95C38"IPS3840x160048-144Hz48-144Hz
LG 34GN85034"IPS3440x1440144Hz48-144Hz
Dell AW2521HF24.5"IPS1920x1080240Hz48-240Hz
Dell AW2521HFL24.5"IPS1920x1080240Hz48-240Hz
ASUS VG259QM24.5"IPS1920x1080240Hz48-240Hz
ASUS PG43UQ43"VA3840x2160120Hz48-120Hz
Acer XB253Q GX24.5"IPS1920x1080240Hz50-240Hz
Acer XV253QX24.5"IPS1920x1080240Hz48-240Hz
Acer VG252Q X24.5"IPS1920x1080240Hz48-240Hz
ASUS VG279QM27"IPS1920x1080240Hz48-240Hz
AOC AG271FZ227"TN1920x1080240Hz48-240Hz
AOC AG271F1G227"TN1920x1080165Hz48-165Hz
Acer XB273GX27"IPS1920x1080240Hz48-240Hz
Acer XB273GP27"IPS1920x1080144Hz48-144Hz
Acer XB323U32"IPS2560x1440165Hz48-165Hz
ASUS VG27B27"TN2560x1440165Hz48-165Hz
ASUS VG27AQL1A27"IPS2560x1440170Hz48-170Hz
Dell S2421HGF24"TN1920x1080144Hz48-144Hz
Lenovo G24-1024"TN1920x1080144Hz48-144Hz
LG 27GN95027"IPS3840x2160144Hz48-144Hz
LG 32GN50T
LG 32GN500
32"165Hz60-165Hz
Samsung C27G75T27"VA2560x1440240Hz60-240Hz
Samsung C32G75T32"VA2560x1440240Hz60-240Hz
Samsung C49G95T49"VA5120x1440240Hz80-240Hz
Acer XB253Q GZ25"IPS1920x1080240Hz50-240Hz
Dell S2721HGF27"VA1920x1080144Hz48-144Hz
Dell S2721DGF27"IPS2560x1440165Hz48-165Hz
Lenovo G25-1025"IPS1920x1080144Hz48-144Hz
Acer XB273U GX27"IPS2560x1440240Hz48-240Hz
Acer VG272 LV27"IPS1920x1080165Hz48-165Hz
Acer XV272 LV27"IPS1920x1080165Hz48-165Hz
Acer CP5271U V27"IPS2560x1440170Hz48-170Hz
Acer X34 GS34"IPS3440x1440180Hz50-180Hz
ASUS PG32932"IPS2560x1440165Hz50-165Hz
I-O DATA GC271HXB27"TN1920x1080165Hz50-165Hz
Lenovo Y25-2525"IPS1920x1080240Hz48-240Hz
Acer CP3271U V27"IPS2560x1440165Hz48-165Hz
ASUS XG27AQ27"IPS2560x1440170Hz48-170Hz
MSI MAG274QRF27"IPS2560x1440165Hz48-165Hz
Xiaomi Mi 245 HF24.5"IPS1920x1080144Hz50-144Hz
Acer XB253QGP24.5"IPS1920x1080144Hz50-144Hz
Acer XB273 GZ27"IPS1920x1080240Hz48-240Hz
Acer XV272 S27"IPS1920x1080165Hz48-165Hz
ASUS VG279QR27"IPS1920x1080165Hz50-165Hz
Lenovo G27Q-2027"IPS2560x1440165Hz48-165Hz
LG 27GP95027"IPS3840x2160144Hz48-144Hz
MSI G273Q27"IPS2560x1440165Hz60-165Hz
Philips 275M1RZ27"IPS2560x1440170Hz60-170Hz
MSI MAG27427"IPS1920x1080165Hz60-165Hz
Philips 275M8RZ27"IPS2560x1440165Hz60-165Hz
ViewSonic XG270Q27"IPS2560x1440165Hz50-165Hz
LG 34GN73A34"IPS2560x1080144Hz50-144Hz
LG 27GN60027"IPS1920x1080144Hz60-144Hz
LG 27GN80027"IPS2560x1440144Hz48-144Hz
LG 27GL83A27"IPS2560x1440144Hz48-144Hz
Gigabyte FI27Q-X27"IPS2560x1440240Hz48-240Hz
Gigabyte FI25F25"IPS1920x1080240Hz48-240Hz
HP Omen 27i27"IPS2560x1440165Hz50-165Hz
I-O Data GC252UX25"TN1920x1080240Hz55-240Hz
Acer XV242Y P24"IPS1920x1080165Hz48-165Hz
Acer XB273U NV27"IPS2560x1440170Hz48-170Hz
Acer XB323U GX32"IPS2560x1440240Hz48-240Hz
Acer XB253Q GW25"IPS1920x1080240Hz50-240Hz
AOC AG273FZE27"IPS1920x1080240Hz48-240Hz
AOC AG273QXP/AG273QCX27"IPS2560x1440165Hz48-165Hz
AOC Q27G2S27"IPS2560x1440165Hz48-165Hz
ASUS VG27AQ1A27"IPS2560x1440144Hz50-144Hz
ASUS VG279QL1A27"IPS1920x1080165Hz48-165Hz
ASUS PG43U43"VA3840x2160120Hz48-120Hz
MSI MAG301RF30"IPS2560x1080200Hz60-200Hz

Note that the monitors listed above will work without any issues, such as flickering, excessive ghosting, and other visual artifacts, with compatible NVIDIA cards.

Other FreeSync monitors may support VRR with NVIDIA cards as well, however, in this case, the performance quality is not guaranteed – they may work just as good, not at all, or have certain issues.

See our list of FreeSync monitors to see which monitors (that we tested) provide stable G-SYNC performance, even though they’re not certified by NVIDIA.

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Rob Shafer
Rob Shafer

Rob is a software engineer with a Bachelor’s degree from the University of Denver. He now works full-time managing DisplayNinja while coding his own projects on the side.