Someone please explain this to me. If ps4 has IO speeds of up to 100 mb p/s, and ps5 has up to 9 gb p/s, does this mean, on ps4, that for every second of screen time, that only 100 mb of data is rendered on screen, or is this a cumulative effect, where every second, 100 mb of extra data is read and added ontop to make more game detail. Like wise with ps5, 9 gb of data maximum per second or cumulative? 

IO speed refers to how quickly data gets into RAM from the hard disk. The speed to get from RAM onto the screen is much, much higher (for example DDR5 is 50Gb/s per channel).

IO is just how fast it loads stuff like textures off of the HDD for models and stuff in game.
Loading screens and storeing things in memory can help too, so your not just limited by that tiny 50mb-100mb HDD speed.

These textures when rendered, take up much more space than when stored on the hdd, their then stored on the GPU memory which moves it around (at faster speeds). Thats why the memory bandwidth of your GPU matters, and the higher the resolutions they render at the worse it gets.

Going from 50-100mb pr sec, hdd speed IO to 8-9GB pr sec, is a huge increase (x90-180 speedup), in how fast data can load from the drives.

The playstation 5 also has like double the memory (16gb) and running at much faster speeds (which is needed for higher resolutions).

Think of Ram as a water tank... And the CPU and GPU as the taps, by constantly running the taps, you lower the tanks water level... So in order to top of up the water tank you need to fill up with more water from the storage drive... An SSD will add water faster than a mechanical HDD.

In short for every second of screen time, the Playstation 4 is able to render up-to 5.5GB of data, because that is how large it's Ram pool is... But over 30 seconds the mechanical hard drive can extend that by an additional 3Gb of data by streaming in assets.

Hope that has cleared it up.

Everyone clinging to certain advertising buzzwords is how the confusion has set in... But it's nice to know every generation we have a group of people who become CPU/Ram/SSD experts over-night, so that's great.

I guess when you say "cumulative" your refering to like loading screens? when you store data off the hard drive into ram?
Yes the IO can load things from the HDD and that speed, and use things stored in memory without effecting each other (as I understand it).

Also 9 GB/s isn't the playstation 5's max.
Its theoretical max is over 20 GB/s, but in "normal" usage its around 8-9 GB/s (it can go higher depending on games and data and how well it compresses).

I liked this way of explaining it.
Water tanks and water taps :)

"In short for every second of screen time, the Playstation 4 is able to render up-to 5.5GB of data, because that is how large it's Ram pool is... But over 30 seconds the mechanical hard drive can extend that by an additional *1,5-3Gb of data by streaming in assets."

So around 8,5 GB over 30 sec (if drive is not anywhere near full or fragmented, and is running near its optimal 100 mb/s).

Playstation 5 could have all that in its memory pool alone.
Or load it in less than 1sec.

Do you know what the maximum data of game textures in gb that can be rendered on screen per second? Just curious as to how much more detail can be shown per frame compared to ps4.

2 things :

how does this relate towards different framerates so a game running 30 fps or 60 fps or even 120 fps?

Does loading 16GB/s into the ram leave room for other tasks?

It doesnt relate to framerates.
It relates to how much details textures can be on screen.

That was why the UE5 demo was impressive.
It showed hollywood movie quality assets, of scanned objects loaded, as 8k textures used on a massive scale.


"Does loading 16GB/s into the ram leave room for other tasks?"
Neither the Xbox SX or the PS5 will fully use that for games.
Nor is loading things into ram pool a static thing, esp now with the SSDs.

Thats the entire logic behinde the claims that the PS5 SSD is so fast, you dont need to keep nearly as much things loaded in the ram anymore.
You can simply load anything on the fly, when needed so fast, it can basically happend as your character is turning around (ei. things out of view, can be loaded in and out of memory, as you move the camra view of your character around).

Basically Ram pool size is more than doubled, and smart techniques and the speed of the SSD IO, will enable you to use ram much more effeciently than before. So even if in actual terms its only perphaps "twice" as much (8gb->16gb) to developers, it will feel like its alot more than that.

so you get the same performance cost with 30fps as with 120fps?