Microsoft DirectStorage slashes the RTX 4090’s speed by 10%

Microsoft’s long-awaited (perhaps-revolutionary) DirectStorage technology finally arrived on the PC this week in Forspoken. Initial testing reports showed encouraging yet mildly perplexing results, with some sections of the game loading in under two seconds flat and continues from your last save point being virtually instantaneous. Yes please! But it appears there’s a tradeoff: Your in-game frame rates decrease by about 10 percent.

That’s what the team at Germany’s PC Games Hardware discovered while putting the Forspoken benchmark through its paces at 4K resolution. The publication used a set testing rig consisting of a Core i9-12900K and Nvidia’s ferocious GeForce RTX 4090, then ran the benchmark from a PCIe 3.0 NVMe SSD, a PCIe 4.0 NVMe SSD, and finally a SATA SSD. The SATA SSD doesn’t support DirectStorage, which requires an NVMe drive.

The end result? The SATA drive delivered the highest average frame rate to the tune of 83.2 frames-per-second. The NVMe drives each averaged roughly 75 fps, a significant 9.64 percent speed reduction. On the positive side, the 1 percent and 0.2 percent frame rates remained consistent across all three drives, so DirectStorage didn’t affect Forspoken’s moment-to-moment smoothness.

Update: There is speculation online that PC Games Hardware incorrectly used the third-party tool CapFrameX to measure its results, including the longer (and higher-performing) black loading screens for the SATA drive, which would obviously increase the overall frame rate for that setup. We’ll update this report with more conclusive information when we receive it.

One of DirectStorage’s key features is decompressing game assets on your graphics card rather than your processor, so it makes sense that overall performance is impacted in some way. Still, a 10 percent frame rate reduction is eye opening. That’s roughly comparable to the jump between an RTX 3080 and 3090, though in real-world terms, the difference between the SATA setup and the NVMe setups were just 8 frames-per-second.

These results aren’t necessarily universal, however. The RTX 4090 is by far the most powerful graphics card on the market and PC Games Hardware only tested at 4K resolution. Performance scaling could change at lower resolutions or on different GPUs with different architectures and memory configurations. (Square Enix did not send out PC review copies, only PlayStation 5 codes, so PC publications are still scrambling to test the new technology.)

It’s also a bit of an open question if Forspoken is an appropriate champion for Microsoft’s ultra-fast new storage tech. Reviewers and users agree that the game is a technical mess on the PC. With no other DirectStorage games to compare results to, who knows if it’s working to its fullest abilities here?

One thing seems clear, though. There ain’t no such thing as a free lunch. DirectStorage may drastically reduce loading times under the right circumstances, but offloading that work to the GPU has consequences elsewhere. It’ll take a lot more testing (and games with DirectStorage support) to fully wrap our heads around everything Microsoft’s forward-looking storage technology has to offer. There’s a Forspoken demo available if you want to try it yourself!

Author: Brad Chacos, Executive editor