BillDStrong

UEFI is a SteamOS Hardware Requirement. Vulkan is not specific to SteamOS.

Vulkan is intended to be used on mobile phones which do not have any type of standard such as this, at least not wide-spread. Vulkan itself has no such requirements.

An individual driver may have such a requirement outside of Vulkan, but that would have to do with the specific driver, and has nothing to do with Vulkan.

It should be noted that SteamOS is based on Debian, and you can pull the SteamOS bits onto a running Debian system, despite whatever BIOS subsytem it is running. So this "requirement" probably has something to do with either the provided installer will only deal with UEFI bios, which is simpler to support, and/or this is a requirement to get a SteamOS logo on your box. If the latter, this may be a sanity check on not using old hardware, since most motherboards now come with UEFI, and would prevent some truly bad/old/slow motherboard combinations.

Does this mean that SPIR-V is not a good optimization target, or would the benefits trickle down?

In regards to the SPIR-V stack of Vulkan/OpenCL, my understanding is that the driver should directly take the SPIR-V code and JIT that directly into machine code.

If we were to use the Gallium stack as a base, would SPIR-V be intended to replace the LLVM-IL based optimizer for the driver, the TGSI compile target, or both? I realize that it was not designed to fit into that stack per se, I am merely trying to understand were it fits.

Or, is that up to the individual drivers?

As opposed to device specific optimizations that would be applied at the IL to (insert asm equivalent here) optimizations.

Thanks, this was a distinction I was missing.

And thanks for this very helpful and informative AMA!!!

If they are already developing a Vulkan implementation of their engine for Linux/Android/Mac, why wouldn't they flip a switch to enable Vulkan support on Windows?

Have the same performance as your competitors that are stuck on Windows 10, but support even Vista, or maybe Windows XP. (Yes, I know that is unrealistic, since no vender still supports Windows XP. )