DirectX 12 Ultimate included in latest driver update.
DirectX 12 Ultimate

Earlier in the day on June 24, Nvidia released a new GeForce Game Ready Driver for RTX and GTX users. Today's latest driver update, 451.48 (WHQL), can be downloaded and installed manually or through the GeForce Experience.

The major inclusion in this driver update is obviously DirectX 12 Ultimate. This driver, coupled with the Windows 10 May 2020 update (version 2004) standardizes a lot of Nvidia's RTX technologies in the DirectX 12 API. This will be used for current and upcoming titles and will bring some RTX features to a few older cards. Don't expect to see much in the way of use for quite some time though. And really, the most visually apparent changes are still limited to those running RTX GPUs on Windows 10 version 2004 or newer.

DirectX 12 Ultimate gives developers a large, multi-platform install base of hardware to target, and ready-made tools and examples to work from -- all backed by time-saving middleware. This makes game development faster and easier, and enables more developers to add these innovative technologies to their games. Many developers have already crafted next-gen experiences featuring these technologies--there are over 30 DirectX Raytracing games shipping or announced--and now with the launch of DirectX 12 Ultimate, adoption of them is set to increase rapidly.
Also included with this driver update and Windows 10 version 2004 is "Hardware-accelerated GPU scheduling." This is a new feature that is built into the latest Windows 10 update and is only able to be enabled with this new driver (or newer) from Nvidia. This feature has the potential to improve performance and reduce latency by allowing the GPU itself to manage its own memory. It won't work across the board in all games. It's also not some miracle update that will suddenly give you an additional 30fps in your games. However, it should smooth out the game and lessen the chance of weird hitching in some titles. As this is a new feature, it is also possible that this option could cause issues in some of your games. If it does, you can turn it off just as easily as you turned it on.

You can enable this in Windows 10 by typing in "graphics settings" from your Start menu. Alternatively, it can be found by going to Settings > System > Display > Scroll to the bottom and click on "Graphics settings." You will need to restart your computer after enabling this setting.

Windows 10 hardware-accelerated GPU scheduling

This driver update also includes support for 9 more G-Sync compatible displays. It also provides full Vulkan 1.2 support for GeForce GPUs. More details can be found at Nvidia.com.

I will also note that some users are reporting that the driver has increased performance in games like Red Dead Redemption 2 and the newest Call of Duty: Modern Warfare.