Cerny said a PS4 hard drive can load 1 GB of data in around 20 seconds, roughly.
I just loaded up my save in The Last of Us Part II from the in game main menu on my PS4 Pro. ("Continue")
It took 90 seconds. The PS4 Pro uses 5.5 GB of RAM, I think. Maybe 5 or 6.
So with Cerny's figure of 1 GB in 20 seconds, that 5.5 GB would take around 110 seconds. My PS4 Pro took 90 seconds, roughly the same as Cerny claimed it takes. (My PS4 Pro has the stock 1 TB HDD fyi.)
If the PS5 SSD is 5.5 GB/s raw, then that game should be able to load in 1 second, not 90 seconds.
But I don't expect it to be that fast. A reasonable expectation for a PS4 game on the SSD would be what? 5 seconds?
Unoptimized regular back compat PS4 games should be able to load in around 5 seconds from the SSD on PS5, and thats only assuming it can hit 1/5 of the raw SSD speed. Some could and should load even faster.
I fail to see how the figure Cerny quoted for PS4 HDD load times are accurate, and confirmed when I test a game load on my PS4, but then somehow the PS5 SSD load times he claims are not to be expected, even with some tempering?
Theres no reason to expect 10+ second load times of PS4 games on PS5 from the SSD. Unless the network is require. I'm of course talking about local singleplayer games.
If it takes even 10 seconds to do the same loading of TLOU2 on PS5 from the SSD that took 90 seconds on my PS4 Pro, then I will be disappointed. It defies basic logic.
I don't expect the exact raw mathematical figure of loading in 1 second, but 5 seconds is reasonable. That's quite a margin I'm giving them.