Sony’s next major PlayStation 4 firmware includes a new system setting, Boost Mode, that enables the PlayStation 4 Pro to deliver better performance for games that don’t explicitly support the beefier console.

Reports of the feature arrived today from PS4 owners who are testing a beta of the upcoming system software update, version 4.50. A screenshot of the PS4’s settings menu, from a tester named Mladen Tapavicki, describes Boost Mode while offering a caveat:

Experience improved gameplay, including higher frame rates, for some games that were released before the introduction of PS4 Pro (CUH-7000 series). Turn this off if you experience unexpected behaviour during gameplay.

You can see the Boost Mode in action in the comparison video above, which shows the opening of Tango Gameworks’ The Evil Within — a game that has not been patched with PS4 Pro support — running with and without Boost Mode enabled. Boost Mode offers a clear frame rate improvement from the very choppy performance of the standard game.

The PS4 Pro, which was released in November, plays every PS4 game. However, developers must specifically patch their games with PS4 Pro support to offer higher-fidelity visuals such as 4K resolution. Even though the PS4 Pro is more than twice as powerful as the original PS4, the Pro doesn’t currently use that extra juice if a game has not been coded to support the system.

Sony’s engineering team designed the PS4 Pro that way on purpose. Mark Cerny, the lead system architect of the PS4, said in an interview with Digital Foundry last year that the company wanted to ensure that every PS4 game would be compatible with the Pro. The simplest way to do that was to beef up the PS4’s GPU while keeping the CPU relatively similar.

“We doubled the GPU size by essentially placing it next to a mirrored version of itself, sort of like the wings of a butterfly,” said Cerny. “That gives us an extremely clean way to support the existing 700 titles.” In essence, the PS4 Pro switches into a non-Pro compatibility mode when it’s running a game that hasn’t been patched to support the console. It only uses half of its GPU at a clock speed similar to that of the launch PS4’s GPU.

That solution avoids problems that can arise by simply throwing more power at a game that wasn’t developed with that increased capability in mind, Cerny explained.

“Moving to a different CPU — even if it’s possible to avoid impact to console cost and form factor — runs the very high risk of many existing titles not working properly,” Cerny told Digital Foundry. “The origin of these problems is that code running on the new CPU runs code at very different timing from the old one, and that can expose bugs in the game that were never encountered before.”

It appears that with Boost Mode, Sony is allowing players to throw that caution to the wind if they want to try to eke higher frame rates out of their games.

Sony has not officially announced a Boost Mode for the PS4 Pro, let alone when it will be released. We’ve reached out to the company for comment, and will update this article with any information we receive.

Update: A Sony representative confirmed to Polygon that Boost Mode is part of the PS4’s v4.50 firmware update. Here’s how the company describes the feature:

Boost Mode lets PS4 Pro run at a higher GPU and CPU clock speed for smoother gameplay on some PS4 games that were released before the launch of PS4 Pro (and has not been updated to support PS4 Pro). Games that have a variable frame rate may benefit from a higher frame rate, and load times may be shorter in some games too.

We’ve edited the article to reflect the statement.

Update 2: Sony is apparently bringing lots of players into the PS4 v4.50 beta, because gameplay videos with Boost Mode enabled are flooding the web from PS4 Pro owners — and as you might expect, results vary from game to game.

It’s also worth noting that Boost Mode will probably only affect frame rates and loading times, as opposed to an actual PS4 Pro patch, which could offer visual improvements like higher resolution and texture detail. But games that use dynamic resolution scaling, like Wolfenstein: The New Order, will likely be able to run with less frequent drops in resolution.

One of the highlights is Avalanche Studios’ Just Cause 3, which ran very poorly on consoles when it launched in December 2015 and didn’t fare much better after five patches. The game is much smoother in Boost Mode, hitting its target frame rate of 30 frames per second much more reliably:

The Witcher 3: Wild Hunt is another game with trouble spots — most notably, swamps like the one in this video from the Blood and Wine expansion. Players who are familiar with The Witcher 3 say that Boost Mode seems to deliver much smoother performance in these areas.

Last but not least, we have FromSoftware’s Bloodborne. Boost Mode seems to provide varying benefits to this action game, and it won’t address the game’s frame-pacing problems. But this video demonstrates a night-and-day difference in the Lecture Hall, especially at the end of the segments (the non-Boost clip is the first one):