

They're making use of the VK_EXT_graphics_pipeline_library extension, which is currently only supported by the NVIDIA Vulkan Beta driver but it will be coming to the stable drivers for all vendors eventually.

Valve say it has a "significant performance improvement aimed at removing hitching when playing with the Vulkan renderer". The Battle Report Update is out now for Dota 2, with the majority of it being for Dota Plus but there's also some of the usual balancing changes and a nice improvement for people using the Vulkan renderer.
