Virtual reality has a very real problem. With several technology giants preparing splashy introductions for the first VR headsets in 2016, few people own hardware capable of fully supporting Facebook’s Oculus Rift or other systems.

Just 13 million PCs worldwide next year will have the graphics capabilities needed to run VR, according to an estimate by Nvidia, the largest maker of computer graphics chips. Those ultra-high-end machines account for fewer than 1 percent of the 1.43 billion PCs expected to be in use globally in 2016, according to research firm Gartner.

VR headsets, which create immersive 3-D environments the wearer can interact with and explore, are poised to be a star of CES 2016. The massive consumer electronics trade show, which kicks off in Las Vegas on Jan. 6, will have more than 40 exhibitors demonstrating VR products, a 77 percent increase from 2015. Taiwanese gadget maker HTC is expected to show off a new version of its Vive headset at CES before releasing it in stores in April. Facebook is still on track to sell its first VR product to consumers by the end of March, Oculus co-founder Palmer Luckey tweeted on Dec. 22.

“I think the technology has significant potential, but I also think we have to be realistic about how strongly it will be adopted in the short term,” Piers Harding-Rolls, an analyst for researcher IHS, wrote in an e-mail. “The hype is somewhat understandable considering the investment some big technology companies are making in VR. However, VR headsets come to market with a number of specific challenges.”

IHS estimates that 7 million VR headsets will be in use by the end of 2016. The Consumer Technology Association, which organizes CES, forecasts VR headset sales of 1.2 million units in 2016. While that’s a sixfold increase from last year with total revenue of $540 million, that’s a ways short of covering the $2 billion Facebook paid for Oculus VR in 2014.

The potential for VR has captivated people’s imaginations and wowed those who have experienced the latest demonstrations. A virtual climb up Mount Everest lets the wearer cross a crevasse on a narrow ladder, inching along as if you really were on the edge of a precipice, or stand on the deck of a sunken ship while ducking under the flipper of a blue whale passing by.

But making the virtual seem so real is hardware-intensive, and most computers struggle to meet the needs of VR. Facebook recommends that Oculus Rift owners have a computer with an Nvidia GeForce 970 or AMD Radeon 290 graphics card. Each costs at least $300. While the graphics card is the big-ticket item, the Oculus Rift will also require other bells and whistles, including an Intel i5-class processor, more than 8 gigabytes of memory, and two USB 3.0 ports.

There’s a very good reason why VR demands such processing power: Anything less, and you might hurl. Early VR prototypes caused many testers to suffer from motion sickness due to slight delays in the screen’s responses to the user’s movements. A standard PC game runs at 30 frames per second. But to deliver the fluid, natural motion our brains need to be convinced an image is real, VR needs to achieve 90 frames per second on two video projections (one for each eye). Right now, that means a $1,500 laptop.

Facebook will start by going after gamers, who are used to dropping big bucks on gaming rigs to play hot PC titles. In a November earnings call, Facebook CEO Mark Zuckerberg said VR will take a while to pick up momentum. “There already is some very good content,” he said. “But until there are millions of units out in the market, I don’t expect that to be a big industry for folks to be investing a huge amount in 2016.”

While the Oculus Rift and the HTC Vive require powerful PCs, that’s not true of every VR device. For example, Sony’s VR headset will work with the PlayStation 4. Samsung Electronics and Google make devices compatible with a smartphone. However, those versions, which rely on a phone’s screen inside a plastic or cardboard case, are rudimentary and risk turning people off to the technology, said Harding-Rolls. “There is a lot of work that still needs to be done before we have a mainstream product with broader appeal beyond early adopter gamers,” he said.

Nvidia is hopeful that VR could help boost a struggling computer market. The company expects the number of VR-capable machines to rise to 100 million by 2020 and said demand for VR could help boost sales of graphics chips.