NVIDIA G-SYNC: Variable Refresh Rate Monitors!

One small step closer to tomorrow’s Holodeck: NVIDIA G-SYNC! It is a technique for refreshing computer monitors at variable intervals (up to a certain limit). Instead of refreshing monitors at exact intervals, the monitor is refreshed when the GPU finishes generating a frame! [Image: AnandTech liveblog of launch event]

Variable refresh rates combines advantages of VSYNC ON (eliminate tearing) with the advantages of VSYNC OFF (low input lag), while virtually eliminating stutters (no mismatch between frame rate and refresh rate).

It is confirmed that this, alone, won’t eliminate motion blur as completely as strobe backlights (e.g. LightBoost), but this is a great step towards eliminating discrete refresh rates (which creates motion blur even at 144Hz. See photos of 60Hz vs 120Hz vs LightBoost), especially as the 144Hz limit is raised in the future, while using nVidia G-SYNC. Hopefully strobe backlight technologies can be combined with G-SYNC in the future — and hopefully already in some upcoming models.

EDIT:
– All G-SYNC monitors include an official strobe backlight mode, better than LightBoost!
– Mark Rejhon has quickly come up with a new method of dynamically blending PWM-free backlight at lower framerates to strobing at higher framerates; see addendum to Electronics Hacking: Creating a Strobe Backlight. This allows combining LightBoost + G-SYNC without creating flicker during lower framerates!

 


About Chief Blur Buster

Mark Rejhon, the founder of Blur Busters.

39 Comments For “NVIDIA G-SYNC: Variable Refresh Rate Monitors!”

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PoWn3d_0704
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PoWn3d_0704

I heard a rumor that you could send in your Asus VG248QE 144hz and get the G-Sync chip installed. The prototypes at PDX LAN this year were simply modified VG248QE’s. Since I have one that would be amazing. After playing CSGO on a GSync monitor I have to say that I can’t wait

Gsync, lightboost, 144hz. I can’t wait.

Also, why doesn’t ToastyX have a 144strobed setting? Why am I stuck at 120?

SpartanGR
Member
SpartanGR

Cause i want a monitor for 3d purposes only (i already own Eizo FG2421). Should i buy one now or should i wait for a G-Sync one?

SpartanGR
Member
SpartanGR

Hi

Do you have a clue if 3d games will see any benefits by G-Sync in terms of gameplay?

Neo
Member
Neo
One more thing I just remembered to mention. Couldn’t backlight strobe timing itself be used to create variable refresh rates? When viewing a strobe display, the light discharge is essentially the actual frame display. LED timing is measured in nanoseconds so it would seem to difficult to synchronize the beginning of a strobe with the source native frame rate. For example a 3:2 pulldown signal could be sent to a 60Hz display but the strobe would flash at multiples of 24Hz ie simulate multiple-shuttering of film projectors. The the difference in LCD refresh rate would be masked the same way… Read more »
Neo
Member
Neo

While doing some lite research I happened upon this older report about Texas Instruments figuring out a way to reduce flicker with PWM lighting. Basically it treats most-significant-bits (MSB) and least-significant-bits (LSB) differently based on how much they contribute to flicker. This should work with the PWM of LCD backlights, as well as OLEDS.

Frame-Rate Technique Delivers Flicker-Free Motion-Picture Performance
http://electronicdesign.com/displays/frame-rate-technique-delivers-flicker-free-motion-picture-performance

I wonder if strobing could also be combined with local dimming (local strobing?) backlights

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