Bad MSAA performance on GTX 760, Linux 64-Bit


I’m trying to enable MSAA for rendering directly into the swapchain. For that I’m using a separate multisample image and do a renderpass-resolve into the swapchain image. However, with an NVIDIA GTX 760 on Linux 64-Bit, Driver 465.31 I’m seeing significantly worse performance with Vulkan than with OpenGL. According to renderdoc my (fairly simple) frame takes ~80us with OpenGL and ~9.2ms with Vulkan, for the same result. I set VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BIT and VK_ATTACHMENT_STORE_OP_DONT_CARE for the MSAA color & depth attachments. Any ideas what I might be doing wrong?