How Microsoft's DirectStorage 1.1 Update Can Seriously Speed Up PC Game Loads
Microsoft teased the next version of DirectStorage technology back in mid-October, saying that it was "coming soon." Well, the developers weren't kidding around, because it's barely three weeks later and DirectStorage 1.1 is now available and ready to use.
Despite the small version number increment, DirectStorage 1.1 is a major step forward for Microsoft's disk I/O API. The new version brings support for the GDeflate compression algorithm that is optimized for use on GPUs. This means that games can transfer assets to the GPU in compressed form and the GPU can decompress them before use.
This saves not only on limited PCIe bandwidth, but also on CPU usage, and it can significantly accelerate decompression, too. That means game developers can make use of the technology to have more detailed assets in the same hardware. The CPU usage benefits could also help out developers with games that are becoming increasingly CPU-limited, at least on the lower-end of their performance spectra.
This isn't the final form of DirectStorage, though. That will come whenever Microsoft finally implements the ability for game assets to stream directly from storage straight across the bus to the GPU. Right now, game assets still have to hit system RAM before they can be prepared to upload to the GPU. This extra step is costly in all kinds of ways, and removing it could drastically improve game performance on PCs.
The requirements to make use of DirectStorage aren't too hard to pass. You need a DirectX 12 GPU—anything reasonably current from Intel, AMD, or NVIDIA will do—as well as a PCIe 3.0 NVMe SSD. There was some chatter in the past about specific performance requirements, but Microsoft isn't mentioning any of that now, at least.
As of yet, no one has implemented DirectStorage in a shipping game. There are reasons to avoid DirectStorage as a developer, the first and foremost being that it will likely be more difficult to support across a variety of platforms. Given the cost of game development these days, most studios prefer to use as few platform-specific features as possible, so we may not see much adoption of DirectStorage, unfortunately—or fortunately, for those playing on Steam Decks and PlayStations.
