# NVK

NVK is a Vulkan driver for NVIDIA GPUs.

## Hardware support

NVK currently supports Turing (RTX 20XX and GTX 16XX) and later GPUs. Eventually, we plan to support as far back as Kepler (GeForce 600 and 700 series) GPUs but anything pre-Turing is currently disabled by default.

## Kernel requirements

NVK requires at least a Linux 6.6 kernel

## Conformance status:

NVK is a conformant Vulkan 1.3 implementation for all Turing (RTX 20XX and GTX 16XX) and later GPUs.

## Debugging

Here are a few environment variable debug environment variables specific to NVK:

NAK_DEBUG

  a comma-separated list of named flags affecting the NVK back-end shader compiler:

  `print`

    Prints the shader at various stages of the compile pipeline

  `serial`

    Forces serial instruction execution; this is often useful for debugging or working around dependency bugs

  `spill`

    Forces the GPR file to a minimal size to test the spilling code

  `annotate`

    Adds extra annotation instructions to the IR to track information from various compile passes

NVK_DEBUG

  a comma-separated list of named flags, which do various things:

  `push`

    Dumps all pushbufs to stderr on submit. This requires that `push_sync` also be set.

  `push_sync`

    Waits for submit to complete before continuing

  `zero_memory`

    Zeros all VkDeviceMemory objects upon creation

  `vm`

    Logs VM binds and unbinds

  `no_cbuf`

    Disables automatic promotion of UBOs to constant buffers

NVK_I_WANT_A_BROKEN_VULKAN_DRIVER

  If defined to `1` or `true`, this will enable enumeration of all GPUs Kepler and later, including GPUs for which hardware support is poorly tested or completely broken. This is intended for developer use only.

## Hardware Documentation

What little documentation we have can be found in the NVIDIA open-gpu-doc repository. The majority of our documentation comes in the form of class headers which describe the class state registers.