.NET 11 raises the hardware bar, dropping support for ancient chips

Microsoft has released the details for the .NET 11 runtime, and it comes with significant changes to its baseline hardware requirements. For both Arm64 and x86/x64 architectures, the minimum supported instruction sets have been raised, moving the ecosystem forward to require more modern CPUs. On Windows, Arm64 now requires the LSE instruction set, while the x86/x64 baseline jumps from x86-64-v1 to x86-64-v2, effectively ending support for processors older than roughly 2013. These changes align with the hardware requirements of Windows 11 and modern server architectures.

For developers, this means applications built with .NET 11 will not run on older hardware, potentially impacting users on legacy systems. The ReadyToRun (R2R) compilation targets have also been updated to take advantage of newer CPU features like LSE and x86-64-v3, which should improve performance on supported hardware but may cause additional jitting overhead on some Linux Arm devices. This move signals a decisive step by Microsoft to leverage modern hardware capabilities, pushing the .NET ecosystem forward while leaving older chips behind.