TECH BRIEF
HDR is coming. But what is it and what does it mean for PC gaming?
Everyone’s talking about ‘HDR’ these days, and if you pay attention to the video settings in PC games, you might be wondering, ‘ What’s the big deal? That’s been around for years!’ Well, I have some news for you. All those ‘HDR’ checkboxes and options you’ve seen in games since Half-Life 2? Turns out that’s not really HDR. That option marked ‘HDR’ in the camera app on your smartphone? That’s not really HDR either.
Lost? Don’t feel bad; when it comes to misconceptions about HDR, that’s just the tip of the iceberg. So just what is HDR and what can it do PC for gaming?
HDR, or High Dynamic Range, is an umbrella term for a series of standards designed to expand the colour and contrast range of video displays far beyond what most current hardware can produce. Despite what you may have heard during the headlong push to 4K, resolution is pretty far down the list when it comes to image quality. Beyond roughly 110dpi under current Windows UI scaling limitations, the number of pixels starts to matter much less than what you do with them.
Contrast, brightness and vibrant colour all become more important to image quality once resolution needs are met, and improving these is what HDR is all about. It’s not an incremental upgrade either; HDR’s radical requirements will mean new hardware for almost everyone and a difference you don’t need a benchmark or trained eyes to perceive.
For starters, HDR specs require a minimum 1,000cd/m2 or nits of brightness for LCD screens to adhere to the new ‘Ultra-HD Premium’ standard. High-end desktop gaming monitors, which top out around 300–400 nits in brightness, don’t come close to making the cut. Good laptops don’t fare much better, since they only push about 100 nits or so more. Even phones, with their sci-fi sunlight-viewable screen technology, only reach about 800 nits.
Colour also gets a makeover with HDR specs requiring a full 10- or 12-bit colour space per channel, which is fully accessible across the OS and managed via a set of active standards. Most PC displays only provide 6- or 8-bit colour per channel.
Currently, PC monitors that support wide gamut colour, or WGC, generally reserve compatibility for professional use, such as photo editing or medical research applications. Games and other software simply ignore the extra colours and often wind up looking misadjusted. HDR standards avoid the confusion by including metadata with the video stream that helps manage the colour space properly.
To help handle all the extra data, HDR also ushers in HDMI 2.0a as a minimum display connector requirement; a long overdue upgrade
on the ubiquitous low-bandwidth HDMI 1.4 standard.
HDR has plenty of promise, but the road ahead isn’t clear yet. The biggest problems aren’t technical roadblocks but competing, partially incompatible standards that threaten to detour early adopters into expensive dead ends. Two main standards for HDR currently exist: the proprietary Dolby Vision and the open standard HDR-10.
PC manufacturers are racing to join in on the HDR phenomenon, but you don’t have to wait for them to try it out. Hardware HDR has already arrived for consumers in the high-end television market. This is also the best way to see the difference HDR makes in action, as a small but growing library of HDR demos, films and television make side-by-side comparison easy.
One place where PCs are already prepared for HDR is the graphics card market. While monitors lag behind their TV counterparts in HDR implementation, mid- and high-end GPUs have been ready for the revolution for almost a year now, thanks to the healthy rivalry between Nvidia and AMD.
The trickier question is what all of this means for PC gamers. While some new games will come out of the box with HDR in mind, older software won’t support the wider colour and contrast capabilities without patching. Those older games may play normally on HDR-equipped systems, but you won’t see any benefits without some fresh code added to the mix.
This means popular games may, in the future, get studio remasters or patches adding HDR support, and the mod community is likely to step in where manufacturers won’t with older classics. Unlike the simulated or averaged HDR found in early games or used in photography, hardware HDR packs a visceral visual punch that’s already catching on in the entertainment industry.
Until HDR patches and games start arriving, however, it’s going to be limited to Blu-ray and streaming content, along with the indignity of seeing consoles get access to enhanced HDR visuals first.