One of the novelties of DirectX 12 Ultimate, the vitaminized model of the DX12 API, is DirectStorage. An API designed in order that graphics playing cards can see reminiscence past their very own VRAM and entry the content material of the NVMe SSDs related to the PCI Express hub of the system.
DirectStorage compatible with NVMe PCIe 3.0 SSDs
Last Tuesday, Microsoft made a presentation concerning the DirectStorage API, which is designed to hurry up the copying of information, which isn’t accessible, from a GPU to an SSD. This characteristic is similar as what NVIDIA calls RTX IO, however inside DirectX 12 Ultimate. Although Microsoft has confirmed that any GPU that’s compatible with DX12 could make use of this API, they advocate activating it in people who meet the necessities of DX 12 Ultimate.
The related info that Microsoft has dropped, by the chat of its presentation, is that DirectStorage works with any of the NVMe SSDs that make use of a PCIe 3.0 or greater interface. Which places an finish to the rumor that DirectStorage would drive the acquisition of NVMe SSDs with PCI Gen four interface.
However, it’s the GPUs compatible with DX12 Ultimate which have built-in accelerators for the decompression of information from the SSD inside. Being the case of the RTX 20 and RTX 30 from NVIDIA and the AMD RX 6000, the remainder of the GPUs regardless of supporting DirectStorage will undergo an affect on their efficiency.
Decompression through Compute Shaders
DirectStorage permits information to be copied from SSD to VRAM with out CPU intervention for decompression, what decreases the latency of entry to such information by the GPU. Microsoft has created plenty of Compute Shader packages that make these run on the GPU. So the identical GPU cores which are used to render the sport will be used to decompress the information.
Since it’s a zero-sum sport, which means the graphics efficiency in video games will be minimize. Unless the GPU is supplied with a specialised drive to decompress information on the fly and handle entry to the SSD. These drives as we’ve defined earlier than are solely discovered on the newer NVIDIA and AMD architectures.
Copying information from the SSD to the GPU in all circumstances means having to order a further a part of the system RAM to carry out this perform. So no matter whether or not the GPU has a decompression unit or not, video games that make use of DirectStorage to repeat information from a PCIe 3.0 SSD onwards are going to require a larger quantity of RAM.
SATA SSDs are out
If you might have a SATA SSD then you definately will not be in a position to make use of DirectStorage, which is a jug of chilly water for many who make use of those arduous drives. The particularity of the PCI Express port is that from which the parts and peripherals related to it may possibly talk not solely with the RAM of the system however with one another.
Because the SATA interface is totally different and doesn’t have direct communication with the RAM, it not solely has decrease bandwidth and its copying system is way slower than by PCI Express. The goal is that the state of affairs has no obvious masses and that the information masses as rapidly as potential whereas we play.
Developers will make use of DirectStorage ultimately, so in case you are contemplating updating your Gaming PC sooner or later then DirectStorage is a robust argument.