DirectStorage is Microsoft’s resolution to modernizing how SSDs are utilized in video games. Because it stands, the SSDs of at present are very restricted by software program relating to information switch speeds, and DirectStorage is just a approach to take away that bottleneck and get video games to make use of the complete power of NVMe/PCIe drives. It even permits your GPU to entry your SSD immediately, bypassing your CPU totally. You’ve got most likely heard that that is going to be nice for reducing down loading instances, and that is the place many of the rhetoric has been centered.
However DirectStorage is not nearly loading instances, and in reality, I would argue loading instances aren’t even the first focus of this new know-how. What DirectStorage is basically about is attaching your SSD to your GPU, and rising graphics efficiency for increased framerates. This might be actually nice for PC gaming and permit avid gamers to take full benefit of PCIe 5.0 SSDs (that are at present not that helpful for gaming), or it is also yet one more factor that makes fashionable GPUs much more abominable.
How DirectStorage could make your SSD as essential as your CPU and GPU
Clearly, SSDs and GPUs are fairly completely different items of {hardware}. You retailer video games on one and run video games off the opposite, and it is probably not apparent {that a} sooner SSD means higher gaming efficiency exterior of loading instances. However all GPUs have one factor: reminiscence, or extra particularly VRAM. At its core, VRAM is only a information storage medium, which is what an SSD is, and whereas GDDR is fairly completely different from NAND flash, they each have one factor in widespread: bandwidth.
Reminiscence bandwidth is a key specification for GPUs. It is decided by a mix of reminiscence bus width, the frequency of reminiscence chips, and what number of reminiscence chips are in use since using a whole reminiscence bus requires a sure variety of chips. Low-end GPUs normally have no less than 100GB/s of bandwidth at their disposal, and higher-end GPUs can simply contact 1TB/s. The bandwidth of SSDs is simply what switch speeds they will hit, which is one thing that SSD producers are likely to promote.
Now, you is perhaps conscious that PCIe 5.0 SSDs will theoretically cap out at 16GB/s, a far cry from even 100GB/s, however that is simply uncooked information. The key sauce of DirectStorage is the truth that it could use the GPU fairly than the CPU for information decompression, so compressing information straight from the SSD and giving it to the GPU is now doable. This additionally has an extra aspect impact of decreasing the load on the CPU.
Microsoft hasn’t but introduced how a lot compression DirectStorage shall be able to, however from what I can collect it’s going to most likely be 5 instances the compression or a little bit extra. That is primarily 5 instances the bandwidth, which implies the quickest PCIe 5.0 SSDs of the longer term can supply as much as 80GB/s of additional bandwidth.
For lower-end and midrange GPUs, it is a fairly huge deal. 80GB/s of additional bandwidth can be a 30% enchancment for the RTX 4060, and roughly 25% enchancment for the RX 7600. The profit is much less clear for high-end GPUs, however it will no less than be a little bit additional. PCIe 6.0 SSDs will improve this to 160GB/s of additional bandwidth, and that’ll be a good larger deal. Heck, a PCIe 4.0 SSD in a handheld gaming PC can be a large increase for built-in graphics, which normally require high-end RAM to carry out properly, even within the case of the Steam Deck.
DirectStorage might be a fantastic factor, or one more reason to impede future GPUs
Supply: Nvidia
One factor I am apprehensive about with DirectStorage is that it may turn out to be much less of a nice-to-have form of function and extra of a your-performance-will-be-awful-if-you-don’t-have-a-fast-SSD form of gimmick. One motive why I am significantly apprehensive about that is that GPU producers (primarily Nvidia and AMD right here) have been making an attempt to economize by slimming down the reminiscence on GPUs for some time now, and whereas a lot of that has to do with capability, it is also about bandwidth.
Lately, we have seen some fairly quick GPUs come out with shockingly small reminiscence bus widths. For example, 256-bit and even 192-bit buses tended to be fairly commonplace for the midrange, however now midrange playing cards just like the RX 7600 and the RTX 4060 are at simply 128-bit buses, which was reserved for a number of the slowest GPUs in lots of collection. Even the RTX 4090 has solely a 384-bit-wide bus, the identical because the RTX 3080 Ti.
After all, there are good causes for Nvidia and AMD to need to lower down bus width: it makes GPUs smaller and thus cheaper to provide, and wider buses require extra reminiscence chips to populate the complete width and get the complete efficiency. Nonetheless, that is in the end a cost-saving measure, and when saving as a lot cash as doable is the aim, it finally ends up creating incentives to compromise a product’s integrity simply shy of crossing the road. Nvidia has completed that with its VRAM on current GPUs, and in some video games, you’ll be able to truly run out of VRAM on a $400+ GPU just like the RTX 3070.
My greatest concern is that DirectStorage will turn out to be a requirement to get a traditional quantity of efficiency out of GPUs if this know-how turns into the usual and even simply widespread sufficient. It will be like a good worse model of the RX 6400, a low-end GPU that requires PCIe 4.0 for good efficiency as a result of AMD put the naked minimal quantity of lanes on it. If everybody wants a top-end PCIe 5.0 SSD to get a GPU operating as anticipated, it’s going to be yet one more barrier to entry for avid gamers with much less means to purchase {hardware}.
The know-how is undeniably cool although
Whereas I’m apprehensive about what incentives DirectStorage may create for GPU design, I do assume it is one thing that would have the facility to essentially enhance gaming. Clearly, recreation devs will have the ability to extract a lot of use out of DirectStorage within the Xbox, the place the {hardware} is simpler to work with, however from what I’ve heard it seems like this know-how shall be plug-and-play, so it ought to work properly on PC with quite a lot of {hardware} configurations.
I am significantly enthusiastic about what DirectStorage may do for built-in graphics like in handheld gaming PCs. The ROG Ally has solely about 100GB/s in reminiscence bandwidth, and DirectStorage may add an additional 25GB/s or so with the quickest 2230-sized PCIe 4.0 SSDs. That might be as much as 40GB/s if sooner 2230-sized drives come out. Take into consideration how briskly the iGPU in your laptop computer or mini PC may get with a quick PCIe 4.0 or 5.0 SSD (as soon as they’re cool sufficient to run with out heatsinks). It may actually increase the viability of low-end, built-in GPUs for gaming, and I would like to see that.
