ToadMan
Member
Does it have two I/O co-processors, DMAC, Sram and coherency engines?
I'm not sure what they do but I'd like to know if the Series X has them or something similar.
I'm really to figure out what the differences are besides the actual hardware of the SSD.
The big difference is this, PS5 can DMA the entire 825gb of it's SSD (It has a custom DMA chip and one of the 2 Coprocessors is used for direct access to SSD storage and indeed is designed around that concept). The Xsex can DMA 100gb - everything outside of that 100gb will need to be paged into the 100gb or accessed more slowly.
Once you understand that, the XVA stuff makes sense - particularly directstorage that is the code handling this stuff.
For Xsex, everything outside the 100gb will have to be paged into the 100gb for Direct access (virtual memory as MS called it) outside of that is presumably a normal file system lookup and is slower as a result.
In order to optimise that, MS need compression and other techniques to avoid games running out of storage which will slow them down as stuff is paged from outside the 100gb region. They'll also need developers to optimisetheir games for that storage paradigm.
I read somewhere that the xb1 bc demo uses about 40gb for a single game save state. So you could only have quick switchable 2.5 games before needing to take the extra time to transfer data from the rest of the SSD. Presumably next gen games will be more than 40gb.
EDIT : I should point out this is based on what we currently know about the systems. Cerny's presentation, the comments from Sweeney and MS's article about 100gb directly being available implying the rest isn't, and using directstorage to limit the cpu hit of storage transfer.
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