[AMD] Celebrating a new generation of UltraHD displays

[DiogoDX]

On the stage in Hawaii last year, amidst the unveiling of the AMD Radeon™ R9 and R7 Series, we mentioned that our GPUs would be ready to support a new generation of UltraHD displays with so-called SST scalers. SST, or single stream transport, promised to make the configuration of 4K monitors easier by eliminating the need for stitching two halves of a display together in software – a staple of first-generation 4K displays. As of late, SST monitors have begun to appear in the market, and we wanted to take some time to talk about their benefits and performance on AMD Radeon™ graphics cards.

SINGLE-STREAM TRANSPORT (SST) vs. MULTI-STREAM TRANSPORT (MST)

When physical LCD panels capable of displaying 3840x2160 content hit the market, the underlying circuitry used to put content on the LCD wasn’t quite as advanced. Part of that circuitry is a critical component known as the “scaler,” which permits the monitor to render pictures at the LCD panel’s native resolution, or at a resolution chosen by the user. Not all monitors have scalers, but many do, especially 4K displays.

The scalers in first-generation 4K panels had a peak resolution of 1920x2160, which is exactly half the resolution of a 4K LCD. At a typical gaming refresh rate of 60 Hz, these scalers simply did not offer enough bandwidth to display a 3840x2160 image 60 times per second.

To address a 4K panel’s full resolution at 60 Hz, two scalers were used simultaneously. Each scaler powered half (1920x2160) of the LCD at 60 Hz, and the signals from these scalers were interleaved within a single DisplayPort™ cable, where an AMD Radeon graphics card would interpret the signal as two separate “tiles” that could be automatically stitched together into a single large surface (figure 2).

FIGURE 2: The “Tiled Display Topology Data Block” standard was one mechanism AMD used to detect the presence of a tiled UltraHD display, then automatically stitch the tiles together for the user.

The technology to carry a signal for two or more monitors on a single cable is called MST, or “multi-stream transport,” a component of the DisplayPort 1.2 specification long supported by AMD Radeon graphics cards. MST is the same feature that has also allowed AMD Radeon GPUs to support multiple monitors from a single DisplayPort output via hubs or daisychaining for many years.1

While MST was a smart and effective solution to bring 4K panels to market at 60 Hz, the graphics industry was already hard at work to realize an ecosystem of support for UltraHD via SST, or “single-stream transport.” These new-generation scalers would have the bandwidth to drive a full 3840x2160 at 60 Hz as a single tile over DisplayPort, which would simplify configuration for the user and help reduce production costs and complexity for the manufacturer.

SUPPORTING 4K60 SST DISPLAYS

Monitors like the Samsung U28D590D (now available) and the upcoming Asus PB287Q are the first of many relatively affordable UltraHD monitors to feature scalers that support 3840x2160 at 60 Hz via SST. Supporting these displays in software, such as with the AMD Catalyst™ graphics driver, is not a trivial matter.

To date, gaming monitors have rarely (if ever) presented such a large rendering surface to the graphics driver. In fact, 2560x1600 monitors presented the largest contiguous block of pixels that would commonly be encountered by a gaming GPU. Every other display configuration, such as a tiled UltraHD display, or an AMD Eyefinity technology configuration, was a larger surface stitched together from many smaller surfaces. Programmatically speaking, all of these are distinct scenarios that must be accounted for with unique code.

Developing that unique code for these new 4K60 SST panels requires a close relationship with the scaler vendors driving these panels. In the case of the in-market Samsung U28D590D, the scaler vendor and AMD worked very closely with prototypical monitors to ensure that AMD Radeon™ graphics cards would be ready to support Samsung’s display when it debuted. More broadly, we are working with all top scaler vendors to ensure our Hawaiian promise that AMD Radeon™ graphics cards will always be the gold standard for UltraHD readiness.

BENCHMARKING SST 4K60

While individual graphics cards like the AMD Radeon™ R9 290X have architectural optimizations to support 4K resolutions, many gamers understandably turn to multi-GPU configurations (e.g. AMD CrossFire™ technology) to squeeze the most performance out of their shiny new UltraHD setup.

In the below performance comparison (figure 3) between the AMD Radeon™ R9 295X2 and SLI GeForce GTX 780 Ti, the benefit of AMD’s robust relationships within the display industry is clear: AMD Catalyst™ is ready to support high-performance gaming experiences on 4K60 SST displays, but our competition clearly has more work to do.

THE GOLD STANDARD FOR ULTRAHD

With a rich history of pioneering new and exciting ways to game on large or multiple displays, we have spent months leveraging that expertise with a number of innovations that have established us as the undisputed leader in UltraHD gaming:
We were the first to equip a graphics card with 64 ROPs to drive the pixel rate demanded of UltraHD displays.
We were first to enable gamers with the ability to stitch tiled 4K displays together via AMD Eyefinity technology.
We were the first to automatically stitch those tiles together with the industry standard Tiled Display Topology Data Block specification.
We were the first to release a single graphics card widely acclaimed for its unprecedented UltraHD performance: the AMD Radeon™ R9 295X2.

And now we are first to market with fully-functional, day-one support for the latest and greatest UltraHD panels with 60 Hz SST scalers. If nothing else, this represents our commitment to serve you – our loyal and enthusiastic customers – with healthy engineering efforts to comprehensively support state-of-the-art gaming experiences.

http://community.amd.com/community/...ebrating-a-new-generation-of-ultrahd-displays

 

[blake0812]

AMD comes out with this and here I am still stuck with 1440x900

 

[x3sphere]

Kind of a pointless benchmark there as SLI isn't working for SST 4K displays yet according to Nvidia, they did say support would come in the next driver update I believe.

Besides that the 295X2 has no HDMI 2.0 port so you cannot game at 60Hz on 4K TV sets. Disappointing for such an expensive card. First card to come out with HDMI 2.0 will get my money.

 

[Skurge]

Hah. AMD taking jabs at nvidia having issues with SST displays.

 

[Techhog]

Oh my god! A correctly scaled graph! I never thought I'd see the day that a chip maker would do this...

And that BF4 result. I guess that's without AA though.

 

[OCGuy]

Wrong forum.....

Hard to read too much into a press release...

 

[BrightCandle]

One of the reasons AMD had to do so much work for SST is that their cards couldn't push enough pixels. In eyefinity resolutions the 7970 has one of the monitors in Windows without Vsync purely to relieve the severe performance problems they have. SST poses a unique problem to AMDs architectural choices.

The issue Nvidia has is very different, its lack of SLI support for SST. They do not as far as I know have to stitch together in software multiple virtual screens like AMD has to because the hardware is capable of this natively. Once they directly support it I suspect we'll be back to the competition being precisely where it was with surround v eyefinity resolutions, ie basically the same but AMD has some weird hacks in place to make it work on many of their cards.

Those living in glass houses shouldn't throw stones.

 

[DiogoDX]

Kind of a pointless benchmark there as SLI isn't working for SST 4K displays yet according to Nvidia, they did say support would come in the next driver update I believe.

Besides that the 295X2 has no HDMI 2.0 port so you cannot game at 60Hz on 4K TV sets. Disappointing for such an expensive card. First card to come out with HDMI 2.0 will get my money.

So you are saing that they have to wait for Nvidia to fix the issue to made tests? Don't remember the "tech sites" waiting for AMD to fix crossfire eyefinity/4K framepacing to do reviews and yet none of they are testing SST 4K monitors.:hmm:

 

[x3sphere]

So you are saing that they have to wait for Nvidia to fix the issue to made tests? Don't remember the "tech sites" waiting for AMD to fix crossfire eyefinity/4K framepacing to do reviews and yet none of they are testing SST 4K monitors.:hmm:

No. They don't have to wait, that's fine, but the benchmark has no value to me. Nvidia will sort out its SST issues soon so this graph will just up being a misleading statistic.

I don't think the framepacing issues are a good comparison. That went on for YEARS, the Samsung 590D only just came out a few weeks ago, and there are no other 4K SST monitors out yet.

 

[KaRLiToS]

I love my 4k Samsung U28D590D with my Quad R9 290x.

One thing I can say, it's really a gold experience.

 

[monstercameron]

I love my 4k Samsung U28D590D with my Quad R9 290x.

One thing I can say, it's really a gold experience.

was that the setup that was annoying you [is this sarcasm?] or is everything running good?

 

[KaRLiToS]

was that the setup that was annoying you [is this sarcasm?] or is everything running good?

The issue I had was with DVI to DP adapters (USB Powered)

I tested another 1440p monitor with my setup, the Asus PB278Q, which is a native displayPort monitor and was working flawlesly. This indicated that it was the adapter that was the issue.

I decided to buy a 28" 4k monitors to replace my middle monitor and I can now run 3840x2160, or 2560x1440, or 7680x1440. I think the 4K sammy is one of the best purchase I did for my computer the last 3 years.

 

[chimaxi83]

Wrong forum.....

Hard to read too much into a press release...

What a surprising post

I'm looking forward to getting a 4K of my own in the next few months, I'm eyeing the one Karlitos bought.


Both of you can stop the bickering before I stop it for you.

-Rvenger

 

[DiogoDX]

28" is too small for me after 4 years with my 32" Samsung TV. My plan is to upgrade to 39" 4K. Big enough to watch movies/tv shows in my bed and and not too big to play games at 1.5m distance.

 

[Leadbox]

One of the reasons AMD had to do so much work for SST is that their cards couldn't push enough pixels. In eyefinity resolutions the 7970 has one of the monitors in Windows without Vsync purely to relieve the severe performance problems they have. SST poses a unique problem to AMDs architectural choices.

The R9 200 series which they're pushing for UHD does things differently