GDC is a major event on the PC gaming calendar. In addition to giving developers a chance to showcase what they’re working on, it also represents a great time to spotlight the technologies that will power tomorrow’s games. One of the games that will explore many new technologies is Renegade from Luminous Productions, and will be one of the first games to take advantage of Microsoft direct storage.
DirectStorage aims to significantly improve loading times in games. If you’re not obsessed with NVMe SSDs, you may have missed the buzz around the technology: a high-speed I/O API that’s comparable to Windows 10 and Windows 11, only it’s also been specifically optimized for Windows 11.
DirectStorage is particularly effective at managing small files, and with it, Forspoken aims to reduce load times from an average of around 10 seconds to a single second. You’re still seeing around 10 seconds on a SATA SSD for gaming and over 30 seconds when loading from a hard drive, but a single second on a high-end NVMe SSD would be a compelling reason to upgrade to the latest technology.
Luminous Productions suggests that DirectStorage is targeting NVMe M.2 SSDs that offer transfer rates of 5,000 MB/s and higher, meaning that many first-generation PCIe 4.0 SSDs are capable of delivering the required performance. The latest PCIe 4.0 drives are capable of reaching 7,000MB/s, so it will be interesting to see if the better SSDs offer a performance boost or if other factors mean it won’t make much of a difference. We’ll have to see when the game actually comes out.
DirectStorage is capable of accelerating various stages of the asset loading workflow, from direct file loading to optimized unzipping and GPU initialization and asset uploading. An important part of DirectStorage is that data loads can run in parallel, with multiple read requests synchronized at the same time for much faster load times, something not possible with traditional file access.
At the presentation, Luminous Technical Director Teppei Ono showed Forspoken loading a scene selection made up of around 20,000 files weighing in at 4.5GB. Load times for these scenes have been shown on NVMe SSDs, SATA SSDs and HDDs to show the difference DirectStorage can make when compared to the traditional Win32 API. The difference was significant.
An M.2 SSD took just 2.2 seconds to load the first scene using DirectStorage, while a SATA SSD took more than twice as long at 4.6 seconds. Meanwhile, the hard drive recorded 24.6 seconds. The second scene had similar numbers, with the M.2 SSD taking 1.9 seconds, the SATA drive taking 3.7 seconds and the HDD bringing the rear at 21.5 seconds.
If you needed a reason to dump your hard drives, this is probably it.
Further analysis of the load times of this scene shows that direct data transfer with compression is only part of the picture, with the DirectStorage API boasting a file I/O speed of 4,839 MB/s versus the Win32 API on the same drive coming in. at 2,826 MB/s. The difference in actual load times isn’t that marked though, at 1.9s versus 2.1s for the Win32 API.
The presentation showed that making the best use of DirectStorage was not simply a case of plugging it into the Luminous engine and forgetting about it. Significant optimizations were needed to get the most out of the technology, and even then, there are bottlenecks in setting up scenes and how things can be improved further. One is the handling of decompression – there are plans for DirectStorage to support direct GPU decompression in the future, which should improve performance even further.
DirectStorage appears to be kick-starting much faster load times, with the potential for near-instant experiences. There’s still a lot of work to be done, but it helps that Forspoken looks great, which highlights what’s possible with the current state of technology.
Forspoken will be released on October 11, 2022.