Home > Computing > What sort of hardware does your PC need to run…

What sort of hardware does your PC need to run stuff at 4K resolution?

Our recent review of the AMD Radeon 295X2, which we benchmarked at both 2560×1440 and 4K resolution, made one thing very clear: running stuff at 4K is difficult.

Setting up a rig to handle Ultra HD is just plain different, right down to the video connections you’ll need to make it work. Different doesn’t mean impossible, however. Here’s what you need to make it work.

4K has issues

A monitor is something people usually buy without putting too much thought into their purchase. There are a lot of solid 1080p options across a variety of price points, and even some 1440p choices are now affordable. Going 4K, however, introduces obstacles you need to be aware of.

The first is resolution relative to screen size. The Windows desktop environment starts to suffer from scaling issues as pixel density approaches 200 pixels per inch. A 30-inch 4K monitor packs a modest 146 PPI, but a 24-incher with the same resolution approaches 184 PPI. That can make desktop icons and Web pages look odd, as if they were out of focus. There are also some scaling problems in certain games, such as League of Legends and World of Warcraft, which have a small default interface scale. Such games provide the option to increase the scale, but that in turn decreases sharpness.

Next up is the two-panel problem. Some 4K monitors attain their resolution by using two individual LCD panels inside the same frame. You can’t see any gaps between them, but your computer will still detect the single monitor as two. This can cause bugs in games, which will sometimes only recognize and run on one “monitor.” In other words, the game will appear on just one half of the display. This setup can also worsen screen tearing issues, and cause interface oddities. In short, we don’t recommend buying a two-panel 4K monitor.

Last, but certainly not least, is the issue of refresh rate. 60Hz, which translates to sixty refreshes per second, has been the gold standard for years. 4K puts such demand on hardware, however, that the chips inside displays can’t always handle it at 60Hz, so some manufacturers have retreated to 30Hz. That means you’ll never see frame rates go above 30 FPS, even if your hardware can manage it, because the display itself updates only 30 times per second.

We expect a lot of these problems will go away over the next year. Samsung, for example, recently introduced a 28-inch 4K monitor that runs at 60Hz and has a single tile.

Learning to love dual GPUs

While your wallet is open for the 4K monitor, you’ll need to keep it open for a high-end graphics card as well. Even the AMD Radeon 295X2, a dual-GPU, water-cooled behemoth, managed only 22 FPS when tasked with running Crysis 3 with graphical settings set to very high. Battlefield 4 didn’t fare much better, scoring a playable, but still slow 37 FPS.

Aside from raw compute power, which is needed to crank out 8.3 million pixels in a 4K image, you also need a lot of video RAM. Our review of the Radeon 295X2 compared it to two Nvidia 780 GTX Ti graphics cards running in SLI. While the 780 Tis performed well in most games, they ran out of steam in Crysis 3, where they put out an average of just 3 FPS. They scored so poorly because they ran out of video RAM, which meant that there wasn’t enough bandwidth available to reliably send the images generated by the GPUs to the monitor.

AMD Radeon R9 295X2 review jacks 1

Ideally, you’ll want not only two powerful GPUs, but also 4GB of video memory per GPU, for a total of 8GB. The Radeon 295X2 offers this, but the GTX 780 Tis have only 6GB (3GB per GPU). That’s why they stumbled in Crysis 3.

The only suitable choices available right now are the previously-mentioned Radeon, or a pair of Nvidia GTX Titans. These provide both the GPU power and memory necessary to game at 4K, but you’ll pay at least $1,500 (for the Radeon 295X2) and potentially up to $2,000 (for the Titans). Nvidia also has a new dual-GPU card on the way, the Titan Z, with 12GB of RAM. However, the expected MSRP is $2,999.

Getting connected

Once you have a 4K monitor and a video card setup that can handle it, you’re done, right? Not quite.

The last hurdle you’ll need to jump through is the connection to the 4K monitor itself. Most PC users are familiar with HDMI, the most common video standard. Almost every 1080p monitor offers HDMI.

Most HDMI connections can’t handle 4K, however. Support for the resolution was only introduced in HDMI 1.4, but even then, only at a maximum of 30 FPS. To drive a 60Hz 4K monitor, you need an HDMI 2.0 cable with an HDMI 2.0 compatible source – and no video card currently sold supports the 2.0 spec.

That means HDMI is out of the question, and so is DVI, because a single cable can only handle a resolution of up to 3840×2400 at 17Hz (33Hz in dual-link mode, which uses two cables – but most monitors don’t support it).

4K monitors that have two screens in a single frame are an exception to the above, because they use two 1080p LCD panels. However, as we already said, a dual-panel monitor is not recommended for the reasons we outlined above.

Acer TA272HUL review hdmi ports

DisplayPort is left as the only option standing, as it’s the only one that can handle 4K resolution at 60Hz and has proper video card support. Even here, though, there’s an obstacle. You’ll need to pick up a DisplayPort 1.2 cable. Older versions of the standard support a maximum resolution of “only” 2560×1600.

Connecting a cable that’s inadequate can result in strange on-screen behavior. The display will likely turn on and transmit an image, but it may flicker, suffer from strange scan lines, or rapidly change color. This can cause some alarm and make you wonder if your new 4K monitor is broken, but don’t worry. Choosing the wrong cable won’t do any damage.

Conclusion

Going 4K isn’t cheap, either. The 28-inch Samsung monitor we mentioned before, when paired with an AMD Radeon 295X2, puts the total cost at about $2,200. That’s also the most economical solution available. Opting for a pair of Titans with a 30-inch display can easily push the total above $4,000.

That’s a lot of money, and shelling out that kind of cash doesn’t guarantee a perfect experience. Even the quickest video cards struggle to keep up with 4K, and there are numerous bugs and scaling issues that may disrupt your experience.

Warnings aside, we can see the appeal. Images are stunningly beautiful at 4K. Even games that are several years old look great, because the extremely high resolution adds details that are simply not visible at lower resolutions. 4K remains too expensive for the average person, but those who can afford it will enjoy jaw-dropping visuals.

Image Credit: Minus/Benjaminthree

Get our Top Stories delivered to your inbox: