{"id":356,"date":"2022-04-06T19:51:16","date_gmt":"2022-04-06T19:51:16","guid":{"rendered":"https:\/\/vrlowdown.com\/?p=356"},"modified":"2022-09-28T20:38:07","modified_gmt":"2022-09-28T20:38:07","slug":"why-is-vr-so-demanding","status":"publish","type":"post","link":"https:\/\/vrlowdown.com\/why-is-vr-so-demanding\/","title":{"rendered":"Why Is VR So Demanding? (And How To Boost Performance)"},"content":{"rendered":"\n
VR has a reputation for being very graphically demanding, requiring high-end hardware to provide a satisfactory experience. But what makes it have such high hardware requirements, and is this ever likely to change?<\/p>\n\n\n\n
VR is graphically demanding because separate high-resolution images must be rendered for each eye at high refresh rates. Modern VR headsets render similar numbers of pixels to a 4K monitor at 90fps. Multiple hardware and software technologies can dramatically decrease the hardware demands of VR.<\/strong><\/p>\n\n\n\n Whilst Virtual Reality has historically been very demanding, the future looks bright, as multiple technologies converge to reduce hardware requirements. Less powerful, standalone headsets have surged in popularity as hardware demands have been mitigated. <\/p>\n\n\n One of the main reasons why VR is more graphically demanding than playing on a flat screen is due to the increase in the number of pixels your hardware has to process, as well as an increase in the frame rate required to produce a smooth and comfortable VR experience. <\/p>\n\n\n\n Below is a table comparing the number of pixels processed by popular VR headsets to those of a selection of flat-screen monitors. <\/p>\n\n\n\n One of the most popular VR headsets, the Quest 2 has a screen resolution per eye of 1832×1920 per eye. This equals 3,517,440 pixels per eye, or 7,034,880 pixels in total. This means that the Quest 2 running at 90Hz needs to process 633,139,200 (7,034,880 x 90) pixels per second.<\/p>\n\n\n\n For comparison, playing a game on PC at 1920 x 1080 (still the most popular resolution) requires 2,073,600 pixels to be processed for each frame. Lower frame rates are also perfectly acceptable for PC gaming, so an application running at 60fps at 1920 x 1080 is processing 124,416,000 pixels per second. This is only one-fifth of the pixels being processed by the Quest 2. <\/p>\n\n\n\n While this seems like a huge jump in the processing power required to run VR applications, there are a number of ways the demand on hardware can be reduced. VR headsets do not have to render apps at the native resolution of the headset, the frame rate can be reduced, and a wide variety of techniques can be employed to reduce hardware demands while still producing smooth gameplay. <\/p>\n\n\n\n You may be wondering how standalone headsets are able to provide a good VR experience when they use hardware that is traditionally used in mobile devices, and much less powerful than desktop PCs. The answer is that standalone headsets often don’t make use of all the available pixels, and frames are rendered using significantly reduced graphical power compared to PC VR applications.<\/p>\n\n\n\n Although the Quest 2, for example, has a resolution of 1832×1920 per eye, the resolution that is rendered by the application can, and often is reduced to decrease the processing power required.<\/strong> This can then be upscaled to the display resolution of the panels, saving processing power, while only having a small impact on visual performance. <\/p>\n\n\n\n Apps and games that are developed for standalone VR headsets are constrained by the limitations of the hardware they are designed for and are highly optimized for the available processing power. Objects and textures are reduced significantly and programs are coded to make use of all the processing power of the headset, while staying within its capabilities, to ensure smooth performance.<\/strong> <\/p>\n\n\n\n A similar process happens when games are coded specifically for games consoles, where the hardware is often weaker on paper than an equivalent PC. <\/p>\n\n\n\n The reality is that standalone headsets are simply not powerful enough to run much of the graphically demanding software that is used on PC VR headsets. However, standalone VR headsets have multiple other benefits and occupy a slightly different market segment. <\/p>\n\n\nWhy Is VR So Demanding?<\/h2>\n\n\n\n
Resolution<\/strong><\/td> Pixels per second<\/strong><\/td><\/tr> Quest 2 at 90fps (1832×1920 per eye)<\/td> 633,139,200<\/td><\/tr> Valve Index at 120fps (1440×1600 per eye)<\/td> 552,960,000<\/td><\/tr> HP Reverb G2 at 90fps (2160×2160 per eye)<\/td> 839,808,000<\/td><\/tr> 1080P monitor at 60fps (1920×1080)<\/td> 124,416,000<\/td><\/tr> 1080P monitor at 90fps (1920×1080)<\/td> 186,624,000<\/td><\/tr> 4K monitor at 60fps (3840\u00d72160)<\/td> 497,664,000<\/td><\/tr> 4K monitor at 90fps (3840\u00d72160)<\/td> 746,496,000<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n Why Is VR So Demanding On PC When It Can Run On A Mobile Chip?<\/h2>\n\n\n\n