Windows 11 is officially out, but if you’ve got an AMD Ryzen processor, you might want to hold off on updating for a bit: the company is reporting that its chips might have issues with the new OS that could cause performance drops of up to 15 percent in some cases.

AMD and Microsoft have found two main issues with Windows 11 on Ryzen. The first is that Windows 11 may cause L3 cache latency to triple. AMD says that the issue could cause 3–5 percent worse performance in most affected applications, while some games (AMD specifically calls out those “commonly used for eSports”) could see performance dips of 10–15 percent.

Windows 11 is also having issues with AMD’s “preferred core” technology, which usually aims to shift threads over to the fastest core on a processor. AMD warns that users could see performance issues on CPU-reliant tasks, specifically on processors with more than eight cores about 65W TDP.

AMD and Microsoft have already confirmed that they are “actively investigating these known issues for resolution via software updates.” The two companies promise that both a Windows update and a software update are planned for later this month to try and resolve those issues. But in the meantime, you might want to stick with Windows 10 until AMD and Microsoft sort things out.