Sarah Tew/CNET

PlayStation 4 fans who have long pegged Microsoft's competing Xbox One as the weaker console may have to rethink their stance on the next-gen graphics crown.

After Xbox head Phil Spencer tweeted yesterday that June Xbox One developer kits would have access to more juice from the console's graphics processing unit (GPU), Microsoft has confirmed that the power boost is not due to a hardware addition, but rather the recent subtraction of the Kinect motion sensor and camera peripheral.

"Yes, the additional resources allow access to up to 10 percent additional GPU performance. We're committed to giving developers new tools and flexibility to make their Xbox One games even better by giving them the option to use the GPU reserve in whatever way is best for them and their games," a Microsoft spokesperson told Eurogamer on Wednesday.

Ahead of this year's E3, taking place in Los Angeles next week, Microsoft has made a number of Xbox announcements, including a few that have turned heads. Many have been aimed at taking the burden off the company as it heads into the expo so that it can focus not so much on the policy and entertainment aspects that embroiled it in a PR nightmare last year, but on the strength of its platform and games.

Notably, Microsoft recently added 45 new Xbox applications, including a much-anticipated HBO Go app for Xbox One. But more contraversial is the decision made last month to unbundle the Kinect from the Xbox One and sell a $399 unit, putting the console on par with Sony's PS4.

The move, made after months of deliberation, marked a stark departure for Microsoft, which has for months been designing its vision for the next-generation of consoles around entertainment and the living room functionality of the Kinect. Microsoft also began taking pre-orders for its second-generation Kinect for Windows sensor Thursday, which it hopes to ship in July concurrently with a beta release of the devices software development kit.

As for the GPU boost for the Kinect-less Xbox One, it doesn't only apply to developer kits or the recent unbundled version of the Xbox One. Any Xbox One not plugged into a Kinect can tap into the performance bump. That's not to say that unplugging your Kinect right now will suddenly spruce up the graphics of the titles in your current library. Rather, it's a software-side capability that allows developers in the future to utilize the hardware differently.

To that end, Microsoft plans to release a software development kit (SDK) later this month that will allow developers to optimize games to take advantage of the system's horsepower freed up from powering the peripheral and applying its functionality to in-game and dashboard features.

That means some games may run faster and smoother, and some titles may look better as well. It all depends on how the extra 10 percent is wielded. But what about the oft-cited gap between Sony's system and Microsoft's when it comes to the number of games running at full 1080p at 60 frames per second?

Microsoft won't say just yet. "How developers choose to access the extra GPU performance for their games will be up to them. We have started working with a number of developers on how they can best take advantage of these changes. We will have more to share in the future," the spokesperson added.

Update at 10:40 a.m. PT: Clarified that unplugging Kinect from current Xbox One consoles does not yield a performance boost; developers must optimize current and future games for the performance boost using Microsoft's soon-to-be-released SDK.