It probably refers to the Series S, as it must be referring to the total amount of memory available.
And please stop repeating this nonsense, no developer needs to determine any of this. The faster bandwidth is primarily used by the GPU, it will hardly use 10 GB, as it needs to be shared with the CPU and for that, the slower speed is more than enough. Apart from the fact that all of this can be used in real time, data structures that require more speed go via the faster bus. The operating system's task scheduler controls this.
He could be talking about any one of those consoles. It would be nice if he had developed it.
The OS can't predict what data the game will use next. It's the game that has to tell the OS, what data goes where.
Something like the dev defining the slower pool to be used as a streaming cache. Or use it as some sort of victim cache, but with memory.
And yes, the slower speed can affect performance, depending on what the game needs at the moment. Especially if it has to shuffle data between one pool and another.
The comparison is bad, because the difference between the memories was much greater, one had a 224-bit bus and the other a mere 32 bits, which resulted in a speed of 196 GB/s in the fastest and only 28 GB/s at the slowest. For most of the 970's life, this was never a problem because at its capacity, few games saturated the 4 GB of VRAM.
The GTX 970 was a good example of the issues that come with having 2 pools of vram , each with it's own speed.
It's a more extreme case than the Series S/X, but it still stands as a cautionary tale.
The XSX:
Memory Config:
10 GB for GPU memory - 320 bit @ 560GB/s
3.5 GB for System CPU - 192 bit @ 336GB/s
2.5 GB reserved by the OS - 192 bit @ 336GB/s
16 GB can be accessed by the GPU but limited to 192 bit after 10 GB has been used. But this will never happen, as memory will always be needed for the CPU.
For comparison purposes, DDR5 memories have an average bandwidth of 64 GB/s and is normally enough for CPUs on PCs.
A kit of DDR5, has much greater bandwidth that just 64 GB/s.
Even a kit of DDR5 dual channel, with a relatively low speed of 6000 Gbps, has a theoretical bandwidth of 96Gb/s.
If we start going to 6400 Gbps kits, we go above the 100Gb/s.
But on PC, it's not important to have high memory bandwidth. CPUs benefit much more from having low latency than memory bandwidth.
That's why it's normal to have DDR5 with latency of 70ns or lower. But with GDDR6, it's more in line with 150ns. Including on consoles.
As you show, the Series X GPU, has basically only 10Gb of memory. So when it needs to use more, it has to shuffle data from one pool to another. Something that the PS5 doesn't need to do.
www.forbes.com
. Phil is Sad.
