AMD demos variable refresh rates at CES 2014

AMD variable refresh rate demo laptops

Variable refresh rates have been a hot topic since Nvidia revealed their plans for gamers with their G-Sync technology, which aims to make V-Sync redundant and smooth out gameplay on hardware that can’t boost framerates beyond 60fps. At their Geforce event held in Montreal, Canada in October 2013, CEO Jen-Hsun Huang was on hand to demo a hardware experience tailored specifically by Nvidia to allow for lag-free gaming. The catch was that the technology needed an expensive card to replace the scaler in a monitor that itself sold for over $500 and only worked with Geforce graphics cards. Many gamers, power users and owners of existing Kepler graphics cards are keen on seeing what the tech can do for them, but the money issue, and the fact that a new monitor is required, is what is preventing them from upgrading.

AMD now says, though, that they can enable similar functionality for no cost at all. All that’s required is a supported monitor and a graphics card from the HD5000 or later families. Read on to find out more.

AMD’s lounge at CES was opened to journalists and both Anandtech and Tech Report were able to get some hands-on time with the demo laptops. They were both pretty low-end units – two Toshiba Satellite Click laptops, sporting 13.3″ screens, 4GB of RAM and AMD’s A4-1200 APU. Its a very cheap chip, all things considered – it only has two cores based on the Piledriver architecture running at 1.0GHz and Radeon HD8180 graphics which are based on the HD6000 family using the older VLIW4 architecture. Performance-wise, its about the equal of Intel’s bog-standard graphics cores found in Sandy Bridge processors.

The Sattelite Clicks themselves also only retail for about $600 and when undocked from the keyboards, become portable tablets running the full version of Windows 8.1.

But the magic is that the demo AMD’s driver team created, which shows a spinning windmill, is fantastically choppy on the laptop to the left, while the right unit, with FreeSync enabled in the drivers, runs through the demo at a much smoother refresh rate. Check out the video below to see what the fuss is all about:


How AMD does this is by enabling support in the drivers to alter the VBLANK intervals, which govern refresh rates, and tell the monitor to only refresh the screen when there is new information to display, rather than having the screen update itself constantly and be forced to splice a new frame with an old one, which is experienced on-screen as tearing. On hand to demo FreeSync was AMD Graphics CTO Raja Koduri.

Koduri explained that AMD had been experimenting and supporting the alteration of VBLANK intervals for some time, but did not encourage monitor or notebook manufacturers to support the feature (now part of the VESA standard) as there was little consumer interest in it. Back in 2012 Intel showed that their hardware for mobile phones and tablets was also capable of the standard and some phone manufacturers already have it enabled on their Android devices.

The reason for the G-Sync hardware, Koduri later told Tech Report, was most likely because Nvidia didn’t see the need for it on their desktop or mobile graphics, as in the past it was expected that most users would be tethered to a wall socket. Altering VBLANK timings was initially another way to save power in laptops, but was not expounded upon when Intel’s dominance in the mobile sector took off and the blue behemoth found that it could save much more power in other areas not related to screen technology.

Nvidia G-Sync partners for 2014
Nvidia G-Sync partners for 2014

Nvidia, seeing the benefits that gamers received from super-high refresh rates and gaming with hacked Lightboost monitors, clearly identified that they needed to add in variable refresh rates for those occasions where performance was not up to scratch, or where players had to dumb down settings to meet a playable framerate. Nvidia’s always been about improving the gaming experience and G-Sync is their effort in making it work. In the architecture that will succeed Kepler, they’re bound to add in the missing functionality that makes G-Sync work and not require special monitors to do it.

In the meantime, though, monitors that have upgradeable firmware could be modified to support FreeSync with little trouble. Because it’s a component of the VESA standard, pretty soon it’ll have to be enabled on every monitor sold in the market. Although it is optional, the cost savings for using cheaper graphics for gaming are not to be ignored, and manufacturers can always find a way of blocking modders from creating their own firmware, allowing them to market some monitors as “gaming” versions of cheaper units.

Sources: Anandtech, Tech Report

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