After HTC's price and pre-order announcement for its Vive VR headset this weekend, Valve has taken the wraps off its SteamVR Performance Test, a simple tool that lets aspiring VR junkies determine what kind of experience to expect from their PC. This test is free, and it doesn't require a VR headset to be hooked up to the host PC to run.
After running a truncated version of Valve's Aperture Science Robot Repair demo for the Vive, the benchmark tells us how many frames are tested, how many frames were delivered "below 90 FPS"—or, we're guessing, how many frames took longer than 11.1 ms to render—and how many frames were CPU-bound.
The test also assigns a performance index to the host system. My Core i5-4690K-powered, GeForce GTX 980 Ti-equipped main desktop scores a 10.9, for example. Swapping in the GeForce GTX 970 from our recent Breadbox build drops that number to a 6. From what we can tell, both tests delivered all of their frames above 90 FPS, and only a couple of frames were CPU-bound.
AMD brought this test to our attention, and the company actually sheds a bit more light on what this benchmark does than Valve's official release notes do. According to AMD, this test uses a technique called dynamic fidelity to adjust image quality to the level needed to maintain a high enough frame rate for a good VR experience.
Going by that description, the rather vague graph in Valve's report seems to tell us how much time cards can spend at various image quality levels. Unsurprisingly, then, the GeForce GTX 980 Ti's flat line at "Very High" means it didn't have to adjust image quality at all, while the GeForce GTX 970's more variable graph might indicate that more on-the-fly graphics settings changes were happening behind the scenes to keep frame times down.
For its part, AMD is pleased about the results its products are delivering with this test. The company has already benched a variety of its graphics cards against the Nvidia competition, using a PC with an Intel Core i7-6700K, 8GB of DDR4-2666 RAM, a Z170 motherboard, Radeon Software 16.1.1 drivers for the Radeons, GeForce driver version 361.91, and Windows 10 64-bit.
All of these results are gleaned from a system with a single graphics card save for one: the dual Radeon R9 Nano configuration you see up top. AMD says those results are the product of an early version of its Affinity Multi-GPU technology, part of the company's LiquidVR SDK. Affinity Multi-GPU lets developers break up the work of rendering a VR scene across multiple graphics cards, and the cards then work together to composite that work together for the final scene. The company warns that its work with Valve on incorporating Affinity Multi-GPU into this demo is far from finished, but it's pleased with the "significant" scaling that Affinity Multi-GPU already exhibits over a single card.
While we're extremely skeptical of the usefulness of an index like this for comparing graphics card performance, the numbers AMD provided do give us a rough picture of how the current players graphics card market might stack up to the challenge of the Vive. Without knowing the exact models of cards that AMD tested, though, it's hard to say much about how well the results of this test map to the real-world options graphics card buyers can choose from.
As expected, though, anybody with a Radeon R9 390, GeForce GTX 970, or better card should be able to enjoy a decent VR experience with the Vive, assuming all titles will target tradeoffs between performance and visual fidelity similar to those that Valve is making in its benchmark.