The Reveal of RTX IO
After months of teases and waiting, Nvidia finally unveiled its new generation of graphics cards, the RTX 3070, 3080, and 3090. Alongside the announcement of these impressively powerful and comparatively inexpensive cards, Nvidia talked about some tech coming alongside them. Perhaps the most interesting of these was RTX IO, Nvidia’s answer to the growing sizes of games and capabilities of NVMe SSDs.
Right now, your PC rarely, if ever, uses its NVMe SSD at full capacity. Unless you’re working in heavy content creation, you’re not getting the most out of it, and even then you might not be. The APIs that manage storage can’t keep up with the speeds NVMe drives are capable of, especially on PCIe Gen 4.
And so here comes RTX IO. Nvidia says that RTX IO is a “suite of technologies that enable rapid GPU-based loading and game asset decompression, accelerating I/O performance by up to 100x over traditional hard drives and storage APIs.”
RTX IO is, in short, the meeting of Nvidia’s RTX hardware and Microsoft’s DirectStorage API. DirectStorage for Windows is the vaunted Xbox Velocity Architecture, but for PC. Microsoft explains that current storage APIs were never optimized for the high number of IO requests made by modern games. “Even with super-fast PC hardware and an NVMe drive, games using the existing APIs will be unable to fully saturate the IO pipeline, leaving precious bandwidth on the table.”
DirectStorage is pretty early on, and many PC configurations won’t support it right now, Microsoft says. A similar comparison for that might be the PlayStation 5’s storage expansion solution. Sony will let you drop in your own NVMe SSD, but it has to be a Sony-approved one for PlayStation 5 games to load off it to ensure there’s enough bandwidth available to function as expected. Similarly, lower-quality NVMe SSDs, certain CPUs, and other hardware may act as bottlenecks that would prevent DirectStorage from functioning.
Even without Nvidia’s RTX IO, DirectStorage promises to be huge for PC gaming as it expands the bandwidth from hundreds of IO requests across a 50MB/s streaming budget to a GB/s budget and tens of thousands of IO requests per second.
Summed up, DirectStorage gives developers direct and less-restricted access to storage, letting them make many more IO requests at any given moment than they can with existing storage APIs.
RTX IO takes out the middle man
Nvidia then takes this and does what every podcast advertisement you’ve heard for mattresses and underwear seems to promise: it cuts out the middle man. RTX IO uses DirectStorage’s increased IO bandwidth and the much faster storage of NVMe SSDs and puts the RTX card in charge of them, offloading “dozens of CPU cores’ worth of work to your RTX GPU” according to Nvidia. It takes the data from your storage and puts it directly in the much faster RTX memory and gives the data to the RTX GPU to sort out.
The RTX GPU will be able to pull compressed data directly from your NVMe storage, where its in its smallest and easiest-to-move form, and let the RTX card decompress it. It skips the CPU and system memory entirely. So with this, your rig will be moving smaller amounts of data and then decompressing them on faster, bespoke hardware; each element speeds up the process of loading both in loading screens and when streaming data from the drive in things like open-world games.
Nvidia says RTX IO will enable “near instantaneous game loading,” improved frame rates, and reduced texture pop-in and game stuttering. Microsoft and Nvidia say that this technology–both DirectStorage on its own and RTX IO as well–will allow games to use heavier compression, reducing overall game size as well.
Future Technology (slow-burn technology)
This is going to be somewhat of a slow-burn technology, though. Nvidia hasn’t said for sure that it’ll be available on RTX 20-series cards, though that seems like it’s very possible. But it’ll also require greater adoption of NVMe SSDs as PC storage solutions and of PCIe Gen 4. It doesn’t seem like PCIe Gen 4 is required, though.
It’ll also require game developers to be on board, to some degree. This stuff works in the upcoming PlayStation 5 and Xbox Series X because developers can target the hardware and APIs in those systems directly. They know what hardware will be available and what that hardware is capable of. A game developer can’t develop a game for a person with an RTX card and a high-end NVMe SSD when there are people out there with AMD cards and games stored on rotational media. AMD will have to present its own IO solution, too, then. That also seems likely considering that AMD is behind the SoCs in the upcoming consoles.
It’ll be huge when it gets here
For those of us with brand new systems, we’ll likely see improvements from RTX IO and DirectStorage immediately. The improvements will only continue, though, as developers start expecting that decompression hardware to be present on GPUs and can build games with it in mind. It seems likely, too, that a suite of other technologies and APIs will begin to accompany this. Developers could have an SSD-optimized installation for those with the hardware to do it, and a bulkier standard installation for the rest of us. It could be something we enable manually or it it could be automated.
There’s no doubt that Nvidia’s 30-series GeForce RTX video cards are a huge jump over the 20-series cards, but RTX IO could be the low-key game changer here in terms of how we play and enjoy games.