Vulkan driver api vs sdk api support

Question

I have NVIDIA driver v 378.92 installed, and according to the nvidia website since driver version 377.14, driver supports vulkan api 1.0.42.1. My vulkan SDK api version is 1.0.42.2. However when I check for my device support info, using vkjson_info.exe in the vulkan SDK, there's stated that only apiVersion 1.0.37 is supported.

I'm a bit confused how this works, can anyone enlighten this?

Answer 1

The reported version could be limited by the Vulkan Loader/Runtime it finds. First is this Windows or Linux?

If you have the Vulkan SDK 1.0.42.2 installed, can you run the VIA tool? It should generate an HTML output. If you look at the "Runtimes" section, you should see which ones are available and which one it's using. For best results, try running it from the same folder as vkjson_info.exe. But, it should give you a good idea if you just run it anywhere.

Answer 2

"1.0.42.1" is not a Vulkan version. Vulkan only has three levels (ie major.minor.patch). So the "1.0.37" is likely correct and the "1.0.42.1" is likely the version of some LunarG Vulkan SDK or possibly Vulkan Runtime that comes with it.

There are usually several types of versions flying around:

• The Vulkan driver version. It is of the major.minor.patch format and it is in VkPhysicalDeviceProperties::apiVersion or can be obtained by a tool such as VHCV .
• Optionally SDK/Layers version on the runtime machine. LunarG Vulkan SDK versioning of the form vulkan_major.vulkan_minor.vulkan_patch.optionally_SDK_patch .
• Vulkan Runtime of the runtime machine — It is basically The Vulkan Loader dll (if the application uses that). Both SDK and drivers install this (and coexist) and they use their own versioning scheme. The SDK version also installs the Validation Layers to the system.
• SDK/Header on the application developer machine. Versioning as described above. The vulkan.h header is always 1.0 and so has only single number version — VK_HEADER_VERSION (which matches the Vulkan patch version — but does not have to in the future)
• SDK/Header on the driver developer machine. Versioning as described above. Should really be the same as Vulkan driver version. And most likely the Vulkan RT installed by the driver will be the same version. But I think I have seen this to differ.

It should not matter, because all patch versions are supposed to be both-ways compatible (in reality not really — there were some changes, but driver makers seem to keep up so far providing updated drivers, so it is not an issue). And in fact that is the only thing I could find in the driver documentation : "Vulkan 1.0" support.

I hope you are so enlightened now that you reached the ultimate state of boredom.

377 is a beta version driver from https://developer.nvidia.com/vulkan-driver . There is no guarantee that beta feature will be carried over to the subsequent release version. And according to http://vulkan.gpuinfo.org/listreports.php it didn't (378 indeed have 1.0.37 and 377 have 1.0.42 and more importantly has the extensions you want to try). Continue to use the beta for now if you want the features within it. As for Layers and other SDK features you should not need newer drivers — in fact you should always use the latest to benefit from Validation Layer bugfixes and improvements.