RTX IO / MS DirectStorage compression

[Shelwien]

https://www.nvidia.com/en-us/geforce...ge-technology/
https://devblogs.microsoft.com/direc...-coming-to-pc/

Nothing here yet: https://docs.microsoft.com/en-us/windows/win32/directx

"Next up, there are the hardware-accelerated decompression blocks. Here’s
where the new BCPack algorithm comes into play — but the XSX also supports
the industry-standard LZ decompressor and can run both simultaneously. This
is where Microsoft’s derived 4.8GB/s of bandwidth comes from. This a 100x
uplift compared with current consoles and, Microsoft says, would require
more than 4 Zen 2 cores to deliver in pure software."

I wonder, is "industry-standard LZ" https://github.com/opencomputeproject/Project-Zipline ?

"I seriously doubt that GPU manages SSD directly. The slide Nvidia showed
yesterday on this one is a bit of generalization. My guess is that RTX IO
is based on Nvidia GPUDirect Storage
https://developer.nvidia.com/blog/gpudirect-storage/ and it does not read
data at HW level on its own but rather provides an interface to CPU (OS) to
feed fetched bits into it (using DMA engine). Put it simple – the main
point here is to skip reading data into RAM first but direct it to GPU
along a shortest path. So OS will keep reading bits from NTFS files but
forwards them directly into GPU."

[Lucas]

I wonder if Nvidia has developed a hardware decompressor for that LZ codec like Sony did for the PS5, or if all the decoding is done using compute shaders with serious amounts of chunking. I’m leaning towards the latter.

[Shelwien]

RTX IO is based on MS DirectStorage, which supposedly already works in the latest Xbox.
So I think that they're talking about some LZ developed by MS - maybe LZX since it was already used on Xbox before this.