Just a few days before it releases Thief, developer Eidos Montreal has announced that the PC version of the game will not support AMD’s “groundbreaking” Mantle graphics API.

Mantle is AMD’s alternative to Microsoft’s DirectX, which aims to greatly improve graphical performance on compatible games and AMD Radeon graphics cards. Thief was going to be one of the first games to take advantage of it.

“We’re extremely proud of the work we’ve done with AMD to make the PC version of Thief a stand-out, definitive experience although we have a little more work to do to accommodate all of these new PC-specific features,” Eidos Montreal said on its website.

The company said it’s working on a patch to support AMD’s Mantle and TrueAudio, which improves audio with certain AMD Radeon GPUs.

The patch is scheduled to release in March. If you own an AMD Radeon card that supports Mantle, you’ll still be able to run Thief, just without the promised performance boost.

“We’re confident this patch will ensure the best and fastest Thief experience for AMD Radeon customers,” Eidos Montreal said. “We’re sorry we couldn’t bring this to you sooner – although we will use this time to bring you the very best experience possible and will let you know when the patch is ready.”

Star Citizen, Sniper Elite 3, and Battlefield 4 are some of the few games that support Mantle. “It is a major change and improvement to how we are able to program and use modern GPUs in order to get the most out of them,” DICE technical director Johan Andersson said.

“Battlefield 4 on PC is already quite heavily optimized using DirectX 11 and DirectX 11.1, but with Mantle we are able to go even further: we’ve significantly reduced CPU cost in our rendering, efficiently parallelized it over multiple CPU cores and reduced overhead in many areas.”

The game’s art technical director Jean-Normand Bucci previously said that Thief will look better on the PC than on the Xbox One or PlayStation 4. He explained that while Thief for the new systems from Microsoft and Sony will deliver “much more” than what console gamers have come to expect, the PC version will go even further.

You can read Thief’s revised PC system requirements on Eidos Montreal’s website.