Want some 4k video with your broadband cap? Good luck with that

Do you have broadband cap anxiety? Then better don’t buy a PS4 (s SNE) when it comes out later this year. Sony’s next generation gaming console will reportedly offer support for 4K video, and the company is looking to launch a 4K video download service to give consumers access to popular fare in the ultra-high-definition video format. There’s just one caveat: 4K downloads will weigh in at a whopping 100 GB a piece, according to a report from the Verge.

Granted, many details of Sony’s plans for 4K aren’t set in stone, in part because the company hasn’t exactly been forthcoming with details about the PS4. But Sony Electronics President and COO Phil Molyneux told the Verge’s Nilay Patel that a typical 4K movie will be “100 gigabytes and plus.”

Just a quick reminder for everyone about to bust out their calculators at home: Comcast’s (S CMCSK) current cap for most of its customers is 300 GB per month, which would get you just three 4K movies, and nothing else. AT&T’s (S ATT) Uverse cap is 250 GB per month. Both companies charge consumers that use more bandwidth $10 per 50 GB, which would bring the bandwidth costs of a single 4K movie after you’ve exhausted your cap to $20.

Of course, Sony may be able to somewhat reduce the size of its 4K movie downloads with advanced compression technologies — but you can only compress a video so much if your goal is to make it look great in 4K on a huge TV set. Throw in something like 3D, and you’re quickly going to hit the cap, no matter what.

Consider this, for example: Streaming a 1080p 3D movie from Netflix currently consumes 4.7 GB per hour. That’s a little more than 7 GB for a 90 minute flick. Now consider that 4K comes with four times as many pixels as 1080p, and some very basic back-of-the-envelope math would suggest that streaming 4K with a Netflix-like compression would lead to at least 28 GB of bandwidth consumption per movie.

So no matter how you look at it: 4K downloads and streams are going to push the envelope on broadband consumption — and could lead to many more consumers running afoul of their caps.