According to the release notes, the new DirectStorage 1.2 will bring the so-called forced buffered IO. Earlier DirectStorage version opened files in unbuffered mode, which avoided unnecessary copies and pushed the data onto the GPU as fast as possible, which is great for SSDs, but some developers requested the buffered IO, which usually means faster performance on legacy hard disk drives (HDDs).

The new DirectStorage 1.2 also gets the new GetCompressionSupport API, which allows developers to check which decompression path is being used, as currently, DirectStorage chooses the decompression path for built-in compression formats based on the supported capabilities of the GPU, and in some scenarios, it ends up on a CPU based fallback path.

The final improvement in DirectStorage 1.2, is a performance improvement that moves the copy after GPU decompression onto the compute queue for GPUs on which this is faster.

There are also several bug fixes, including:

• Resolved https://github.com/microsoft/DirectStorage/issues/22 by adding a “Reserved1” field to DSTORAGE_REQUEST_OPTIONS. This makes the in-memory layout of the structure more explicit but doesn’t actually change the layout from previous versions.
• Fixed DSTORAGE_REQUEST_DESTINATION_TEXTURE_REGION for 3D textures, as reported to us on the DirectX Discord channel.
• Fixed scheduling issue that manifested when transferring uncompressed data from memory to buffers

You can check out more information over at Microsoft's DirectStorage landing page.