Revolutionizing Displays to Improve Game Play

by Tom Petersen

Montreal, to me, has always meant hockey masks, maple syrup and Mounties. I never thought it was the doorway to gaming heaven.

But when we launched NVIDIA G-SYNC here today, I could see my life as a gamer getting better. Actually, I could see the rest of my life getting better, too, because we’ve been working flat out to get this out the door for several years.

The idea behind G-SYNC is simple, even if the technology isn’t. It’s to deliver visually stunning games, without the artifacts that jolt you out of the zone – like a guy who keeps standing up in front of you during a great movie.

Gaming headaches? Take one of these and call us in the morning.

An Obstacle to Great Gaming

Now, I’ve been gaming on PCs for just about 20 years. I started out with “Doom” and “Descent.” Ever since, I’ve been reaching for the hard stuff. A perfect evening for me is coming home after a long day at NVIDIA, cracking open a Guinness and sitting down to a session of “Starcraft II.” Or even better, jumping into a new indie release like “Antichamber.” That thing still blows my mind.

But much as I love gaming, I’ve always hated the choices you have to make synchronizing to your monitor. With V-SYNC off you can have fast input response time, but images are seriously corrupted by tearing. Or, you can use V-SYNC on, but then games get laggy, and any time the GPU’s FPS falls below the refresh rate of the monitor, animation stutters badly.

Imagine if your fully armed buddies can see you. But your system won’t let you see them. The input lag can get you killed. Given the options, it’s not surprising that competitive gamers pick the lesser of two evils and run with V-SYNC off. But it’s still short of perfection.

What I want from gaming is to get immersed in the experience. I want to feel the cracked concrete under my feet. Or the buzzing jungle closing in around me. Or the flash of the grenade nearby. Stuttering and tearing are distortions that bring me back to the beige carpet in my game lounge. They make me wonder what caused them and I get jolted out of the zone pretty fast.

G-Sync: your ticket to gaming nirvana.

Getting to the Root of The Problem

This same observation got Jen-Hsun, our CEO, to commission some of the brightest minds at NVIDIA to solve this problem. We brought together about two dozen GPU architects and other senior guys to take apart the problem and look at why some games are smooth and others aren’t.

It turns out that our entire industry has been syncing the GPU’s frame-rendering rate to the monitor’s refresh rate – usually 60Hz – and it’s this syncing that’s causing a lot of the problems.

Sadly, monitors, for historic reasons, have fixed refresh rates at 60Hz. That’s because PC monitors initially used a lot of technology from TVs, and in the U.S. we standardized on a 60Hz refresh way back in the 1940s, around the time Ed Sullivan was still a fresh face. That occurred because the U.S. power grid is based on 60Hz AC power, and setting TV refresh rates to match that made early electronics easier to build for TVs. The PC industry just sort of inherited this behavior because TVs were the low-cost way to get a display.

So back at NVIDIA, we began to question whether we shouldn’t do it the other way. Instead of trying to get a GPU’s output to synchronize with a monitor refresh, what if we synchronized the monitor refresh to the GPU render rate?

No More Tearing, No More Stutters

Hundreds of engineer-years later, we’ve developed the G-SYNC module. It’s built to fit inside a display and work with the hardware and software in most of our GeForce GTX GPUs.

With G-SYNC, the monitor begins a refresh cycle right after each frame is completely rendered on the GPU. Since the GPU renders with variable time, the refresh of the monitor now has no fixed rate.

This brings big benefits for gamers. First, since the GPU drives the timing of the refresh, the monitor is always in sync with the GPU. So, no more tearing. Second, the monitor update is in perfect harmony with the GPU at any FPS. So, no more stutters, because even as scene complexity is changing, the GPU and monitor remain in sync. Also, you get the same great response time that competitive gamers get by turning off V-SYNC.

G-SYNC moves us a little closer to gaming nirvana – a world of great image quality with no tearing, no monitor stutter, and really fast input response. That lets me get back in the zone when I game. Already, I can see my beige shag carpet and Costco art prints in their crooked frames slowly replaced by the hard rock roads and dragon fire of “Skyrim.”

Life is good again.