At the moment, DirectStorage on PC has only been used in a single title, Forspoken, a Square-Enix title that has passed with more pain than glory among the new PC games that came out last year. However, there is a reason for this that explains the disuse of this technology by the PC video game industry.
DirectStorage on PC is not the same as on Xbox
To understand why DirectStorage on PC is a bad idea, we have to start from something that we all know by now: PC and console use different RAM configurations. And no, we are not referring to the amount or type of memory. If not, which video memory and RAM memory are not physically separate entities on a console, on the other hand, they are on a PC and that is where the DirectStorage problem lies.
The key on the console, specifically on the Xbox Series, but PS5 has an identical system, is that within its 16 GB an exclusive part is assigned for the graphics card. But in order to copy the data from the SSD it is a memory leap only due to the fact that there is only one physical memory. On the other hand, if we talk about the PC, things change, since it has to be copied from the SSD to the RAM and from this to the video memory. And what advantage does this have? Well, less than on the console, only that the copy process can be carried out by the graphics card, but we still need a large amount of backup memory in the system memory.
Ideally, the copy from the SSD to the GPU would be, but it is not possible, rather Microsoft sells DirectStorage as a way of offloading the CPU from the loading process and it is a function that has been in graphics cards since 2018, in Specifically, the first to include it were the RTX 20 under the name of RTX IO, but today all the latest generation graphics cards have it regardless of brand.
Consoles have specialized hardware, PCs don’t.
The only major change to DirectStorage is to make the GPU on the graphics card do the high-speed data decompression, both for its own use and for leaving it in system RAM. This means wasting graphics resources to make a function that on consoles is executed through a specialized processor, for which it is found as a main complement in the chip of all new generation consoles. That is to say, that when they decompress the data from the SSD on the fly they are not consuming resources neither from your CPU nor from your graphics chip, with the PC version of DirectStorage it is and that is the biggest problem.
Worst of all, this process on consoles is completely automated, the games are compressed on Xbox and programmers don’t have to worry about the compression and decompression work. On the other hand, on PC it is necessary to program it. Hence its absolute level of disuse in PC games today, despite the fact that it is a technology that is already available. What’s more, if you remove the decompression it is possible to use it on graphics cards that are not DX12 Ultimate, but in any case we highly doubt that developers want to use it on PC.
Why is DirectStorage almost not being used in PC games?
The reason for this is simple, in consoles they are limited by the size of the chip and, therefore, they cannot add more CPU cores, hence they use specialized units. Not only that, but on computers there are no problems in raising the requirements of the games in this sense, on the other hand, on consoles the hardware is fixed.
But there is an additional issue that is the PC’s RAM memory, if it is necessary to access the SSD continuously to dump the data on consoles it is due to lack of space. However, the most searched for in games are not large amounts that are sequentially streamed for an install, but small files that are randomly searched for. In any case, we have that on the console these are transmitted to the space that we have available in RAM, does the same happen on PC? No, it reads from system RAM and many titles use system RAM as backup media.
That is, regardless of the format that we are using for storage, what is done on PC is to use a greater amount of RAM memory to store that data. At the end of the day, accessing it is faster than doing it to the SSD. Well, even with DirectStorage on PC you are not accessing the solid state drive, but rather a copy in RAM and you don’t need to use it for that.
