On February 1st, NVIDIA released a new developer beta driver, which fixes a couple of issues with their Vulkan API implementation. Unlike what some sites have been reporting, you should not download it to play games that use the Vulkan API, like DOOM. In short, it is designed for developers, not end-users. The goal is to provide correct results when software interacts with the driver, not the best gaming performance or anything like that.
In a little more detail, it looks like 376.80 implements the Vulkan 188.8.131.52 SDK. This update addresses two issues with accessing devices and extensions, under certain conditions, when using the 184.108.40.206 SDK. 220.127.116.11 was released on January 23rd, and thus it will not even be a part of current video games. Even worse, it, like most graphics drivers for software developers, is based on the old, GeForce 376 branch, so it won’t even have NVIDIA’s most recent fixes and optimizations. NVIDIA does this so they can add or change the features that Vulkan developers require without needing to roll-in patches every time they make a "Game Ready" optimization or something. There is no reason to use this driver unless you are developing Vulkan applications, and you want to try out the new extensions. It will eventually make it to end users… when it's time.
If you are wishing to develop software using Vulkan’s bleeding-edge features, then check out NVIDIA’s developer portal to pick up the latest drivers. Basically everyone else should use 378.49 or its 378.57 hotfix.