Xbox Series X killer feature revealed — and PS5 should take notice

Halo Xbox Series X
(Image credit: Microsoft)

The Xbox Series X will be backwards compatible with just about every Xbox One game, as well as hundreds of Xbox 360 games and a handful of original Xbox games. We've known that for a while, but now, Microsoft has given us details on just how ambitious its backwards compatibility plan is. 

The Xbox Series X doesn't just have the capacity to run old games — it has the capacity to run them at higher resolutions, and at faster frame rates, than they could achieve on older systems. To make this happen, Microsoft has invested more than 100,000 hours in testing the process.

Information comes from a blog post on the official Xbox site, written by Jason Ronald, the director of program management for the Xbox Series X. A lot of Ronald's blog describes things we already knew about the upcoming console: Backwards compatibility will be available on launch day, and it will include thousands of titles, including more than 500 Xbox 360 games.

While the Xbox Series X should theoretically be compatible with any Xbox One game, Microsoft has spent a considerable amount of time testing games to verify compatibility.

"With more than 100,000 hours of play testing already completed, thousands of games are already playable on Xbox Series X today, from the biggest blockbusters to cult classics and fan favorites," Ronald writes. "Many of us in Team Xbox play on the Xbox Series X daily as our primary console and switching between generations is seamless. By the time we launch this holiday, the team will have spent well over 200,000 hours ensuring your game library is ready for you to jump in immediately."

What's potentially more interesting, however, is Ronald's assertion that these old games could look better and play more smoothly than ever before.

"Backwards compatible games run natively on the Xbox Series X hardware, running with the full power of the CPU, GPU and the SSD. No boost mode, no down clocking, the full power of the Xbox Series X for each and every backward compatible game," he wrote. "Titles [can] render with increased resolutions up to 4K … We are also creating whole new classes of innovations including the ability to double the frame rate of a select set of titles from 30 fps to 60 fps or 60 fps to 120 fps."

Does this mean that every backwards compatible title on the Xbox Series X will run at 4K resolution and 120 frames per second? Probably not, considering that most titles developed for the Xbox Series X will target 4K at 60 fps. But some older games will get very high resolutions, and some older games will get very fast frame rates, and that's pretty impressive, when you consider that many of them maxed out at 1080p and 30 fps on their native systems.

Ronald also mentioned that the Xbox team is eager to hear from fans about which titles they'd like to see optimized. Backwards compatibility "presents a complex mix of technical and licensing challenges," he said, so not every favorite title is going to wind up on the Xbox Series X. But having some is better than having none, and it's always fun to revisit your favorites.

Marshall Honorof

Marshall Honorof is a senior editor for Tom's Guide, overseeing the site's coverage of gaming hardware and software. He comes from a science writing background, having studied paleomammalogy, biological anthropology, and the history of science and technology. After hours, you can find him practicing taekwondo or doing deep dives on classic sci-fi. 

  • PUB_Luigi
    I've been wanting to play afro samurai for some time now but the PS4 doesn't support backwards compatibility with PS3 games. Not a big deal as I'm not really one to dive deep into the back catalogue of games but having owned an Xbox 360 in the previous generation, I probably would have a lot more I'd want to try again if I made the jump back to MS with the Series X!