AMD’s FreeSync variable-refresh-rate technology has a lot going for it these days. Just pick out any FreeSync display you like on Newegg or Amazon and compare it to a similar display with Nvidia’s G-Sync tech on board. More likely than not, the FreeSync display will be a cool Franklin or two cheaper than its G-Sync competitor. FreeSync displays tend to have more input options than G-Sync monitors, too. The green team’s VRR (variable refresh-rate) screens often make do with a single DisplayPort connector. Intel has also confirmed that it’ll support the standard that underpins FreeSync—VESA Adaptive-Sync—in its future products. Given how many graphics processors Intel ships in its CPUs, its backing of Adaptive-Sync could have a decisive effect on the eventual outcome of the VRR wars.
In 2016, AMD wants to make FreeSync better and more broadly available. First, it’s bringing FreeSync to HDMI ports on compatible laptops and desktops. Second, it’s building support for DisplayPort 1.3 (with the High Bit Rate 3 link option) into its next-generation graphics processors. DP 1.3 with HBR3 offers a major increase in potential bandwidth, and AMD will put that extra throughput to use in some exciting ways. Third, FreeSync is coming to gaming notebooks.
AMD detailed these developments for us last week at a tech summit held by its Radeon Technologies Group. Let’s dive in.
FreeSync over HDMI brings buttery smoothness to more ports
We’ve already seen some improvements to FreeSync this year. In its Radeon Software Crimson Edition driver update, AMD enabled a feature called Low Framerate Compensation (LFC) for FreeSync displays whose maximum refresh rates are at least 2.5 times their minimum rates.
We now know that LFC’s software algorithm looks at frame times and sends additional frames to the display as needed to keep motion smoother when frame rates drop below the display’s minimum refresh rate. This improved method is a much-needed bit of polish, and we’re glad to have it.
In its present form, FreeSync requires a DisplayPort connection to function. That’s because VESA Adaptive-Sync, the technology that underpins FreeSync, is part of the DisplayPort spec. Most graphics cards have at least one DisplayPort output these days, but HDMI ports are even more common, especially on laptops. Problem is, the HDMI spec doesn’t include any kind of provision for VRR tech right now, so unless you have a fancy graphics card with a lot of DisplayPort outputs, configurations like a large FreeSync Eyefinity group could be hard to set up.
AMD wanted to bring FreeSync support to HDMI ports without waiting for the next HDMI revision, so it’s taking advantage of a feature called vendor-specific extensions to amend the HDMI spec for variable-refresh operation. This extension will allow present and future Radeons to talk to FreeSync-capable displays over HDMI.
Although AMD’s use of vendor-specific extensions may seem like the company is jumping the gun, it assures us that the move isn’t a risky one. If variable-refresh support is included in a future HDMI specification, that spec should be able to coexist peacefully with products that support AMD’s extensions. The company expects that its hardware should be compatible with a future HDMI specification for VRR operation, too.
FreeSync over HDMI will begin rolling out to Radeons that can already do the VRR dance in the first quarter of 2016, but monitor makers will have to build support for the tech into new displays. AMD has already partnered with Acer, LG, and Samsung to develop a number of HDMI-FreeSync compatible monitors in a dizzying array of aspect ratios and screen sizes. The company is working with Mstar, Novatek, and Realtek to incorporate its extensions into those companies’ display controller chips, as well.
FreeSync over HDMI is also coming to laptops with both an AMD APU and Radeon discrete graphics inside. The company’s extensions mean that laptops with those components will be able to perform VRR over their external HDMI ports, too.
DisplayPort 1.3’s copious bandwidth lets UHD content shine
Although we can’t share many details of them yet, AMD gave us a high-level overview of its next-generation Radeons last week. One of the tantalizing features baked into these upcoming GPUs is support for DisplayPort 1.3 with the High Bit Rate 3 link option. This type of DisplayPort link offers a whopping 32.4 Gbps of bandwidth, about 80% more than HDMI 2.0, and it can move all those bits using existing cables and connectors. DP 1.3 has several exciting implications for next-generation FreeSync displays, as well as for higher-resolution panels like 5K screens.
For one, DP 1.3 can drive 4K (or 3840×2160) displays with full color data at up to 120Hz. DP 1.3 also allows a graphics card to drive a 5K (5120×2880) display over a single cable at 60Hz with full RGB color. Consider that a 5K display has 78% more pixels than consumer 4K displays, and you start to get a feeling for just how much data is moving across that single DisplayPort 1.3 link.
That extra bandwidth isn’t just for driving gobs of pixels, though. A theme of AMD’s summit was making “better pixels,” not just more pixels. By AMD’s definition, better pixels will be produced with a wider color gamut and a broader dynamic range. To guide this effort, the company has taken a page or two from the burgeoning ultra-high-definition (UHD) segment of the consumer electronics industry .
UHD content can be produced with an extremely wide color gamut (Rec. 2020). UHD also uses a modern transfer function (SMPTE ST 2084) to encode a wider range of brightness values for UHD TVs and monitors, commonly known as high dynamic range, or HDR.
For reference, AMD says typical consumer displays today range from about 0.1 to 250 nits of brightness. Those displays also use the relatively narrow sRGB color space and a transfer function designed to mimic the characteristics of CRT displays (Rec. 1886). That function only accounts for a brightness range up to 100 nits, and it’s poor at encoding the darker parts of an image.
UHD OLED displays could boost that maximum brightness to 500 nits (with pure blacks, thanks to the underlying display technology), while future LCDs could range from 0.0005 to 1000 or even 2000 nits next year. Those LCDs are will likely use local backlight dimming to acheive higher contrast.
10-bit color support is a rarity on today’s displays, but AMD expects it’ll be a key feature of displays going forward to support the wider color ranges required by UHD content.
Another piece of the UHD puzzle on the PC is Windows’ support for 10-bit color and HDR. Right now, Windows offers limited support for 10-bit applications, and the OS doesn’t support HDR content at all.
AMD says it can get around these issues for the moment by rendering UHD content in an exclusive full-screen context, since that mode bypasses Windows’ limitations. That’s not an ideal situation, but it should work fine for activities like gaming and movie-watching that are generally full-screen in the first place. As UHD content becomes more common, we’d expect that Microsoft will develop more fine-grained ways of handling and displaying that content outside of a full-screen context.
Today’s Radeon graphics cards will be able to support UHD gaming and photos, while those next-generation Radeons with HDMI 2.0a and DisplayPort 1.3 will be able to output 4K UHD content (including movies) at up to 60 frames per second with 10 bits per color channel.
The Radeon Technologies Group had a couple of UHD displays running HDR at its tech summit to demonstrate UHD content, and we were impressed by the clearer, more natural-looking images these displays showed, especially next to a (frankly broken-looking) conventional HDTV. The ugly tone-mapping that might have reared its head in older games on conventional displays was nowhere to be seen. UHD will probably get a lot of hype from consumer electronics companies soon, but based on these quick previews, we think these displays (and the content they’ll show) will be an exciting advancement.
You can see some examples of the higher refresh rates and different content types that DP 1.3 monitors may support in AMD’s image above. We’re most excited about the expected specifications of those 2560×1440 and 3440×1440 displays. 170Hz or 144Hz HDR content with FreeSync enabled? Sounds great.
Don’t expect these panels to hit the market immediately, though. AMD projects that single-cable-ready 5K displays will arrive in mid-2016, while 120Hz 4K panels with FreeSync support are expected to arrive in the fourth quarter of 2016. Even so, these higher-refresh-rate displays sound like they could herald a bold new era for the gaming monitor, and it’ll be interesting to see what GPUs AMD has up its sleeve to drive them.
FreeSync goes mobile, too
Gaming notebooks with Nvidia’s G-Sync onboard have been available for a while, and now AMD is getting in on the mobile variable-refresh game from a somewhat more entry-level angle. The one qualification is that any discrete Radeons must be driving the laptop’s internal display directly, not through an Intel IGP. The company unveiled the first of these notebooks, a FreeSync-enabled version of Lenovo’s Y700 laptop, at its summit.
This machine has a 15.6″ 1080p display that can run in a VRR range of 40 to 60Hz. While it’s nice to see FreeSync make its mobile debut, we’ve got to pick a nit. Given the demands of FreeSync’s LFC tech, we’d have loved to have seen a display with a broader refresh-rate range, like 30 to 75Hz at a minimum.
This particular Y700 is a fairly nice-looking machine that’s powered by an FX-8800P APU and Radeon R9 M380 graphics. The FreeSync panel doesn’t use a scaler chip, a typical configuration for a notebook. Instead, AMD uses some of the FX-8800P’s resources as a display controller to make the VRR magic happen.
AMD didn’t provide the full specs of this red-blooded Y700, but we did some investigating for an idea of what this machine’s $899 list price gets you. The R9 M380 graphics chip uses 10 GCN compute cores for a total of 640 stream processors, clocked at a round 1000MHz. AMD’s specs say the M380’s 128-bit memory bus can be joined to up to 4GB of GDDR5 memory running at up to 1500MHz. Based on those specs, the M380 should slot in somewhere between the GeForce GTX 950M and GTX 960M.
Mobile G-Sync is only available in notebooks with GeForce GTX 965M cards and better, and notebook makers seem to have reserved the feature for the $1500-ish price bracket, so Lenovo’s Y700 could represent a nice way to get VRR on the go for less. It remains to be seen how many other manufacturers will hop onto the mobile FreeSync bandwagon.