PS4 backwards compatibility with PS3 games (stored on an external hdd or ssd)

[First_Knight]

I still have a 'fat' PS3 (750gb+ hdd storage) used mostly for watching Blu-Ray DVD's but also for occasionally playing games (from a disc) that do NOT require an internet connection to work. I don't care enough about 'online games for multi player options', to even start that, & if a console MUST be online to play the game I am also not interested either, since my internet is far too slow for cloud based gameplay, on ANY games machine.

I have about 85 disc based PS3 games, plus a lot of associated updates & DLC & 'free' games aquired BEFORE online multiplayer gaming REQUIRED a subscription.

My question is based on something I saw recently on Youtube about PS5 backwards compatibilty with PS4 games:

i.e. that PS4 games could be stored completely on an external hd (presumably an SSD) with updates & game saves included (so the disc is no longer needed to play the game) & either played from the external drive on a PS4 or even on a PS5 - that can NOT apparently play that same game from the PS4 disc.

Is this true?

If it is, is it also possible to do the same (in November 2020) with PS3 disc based games stored on an external ssd to play them on a PS4?

& How would the game be completely stored on an external hdd or ssd anyway (whether that be a PS3 game to be played via a PS4, or a PS4 game to be played via a PS4 or PS5)?

Would it be 'easier' just to get at least some of these PS3 games downloaded to a PS4 for OFFline gaming wherever it is stored - is that even (still) possible?

I do NOT own either a PS4 or a PS5.

I would rather get a PS4 if I can, since no PS5's are available & they cost double that of a PS4 Slim.

Also, should the PSN still work with a PS3?

Many thanks for any info

😀

[RottenFoxBreath]

First point, yes you can install ps4 games on a hard drive/ssd, and play them on a ps5, but there are some that do not work.

You cannot play ps3 games on a ps4/ps5, you need Playstation Now for that, but that's online streaming/downloading, and a monthly/yearly fee.

And in turn, all the other points are moot.

[Lord_viridis]

Yes as @RottenFoxBreath said PS4 to PS5 is possible using external drives with discs installing, even on the internal SSD if needed. But... Sadly PS3 games won't be possible through backwards compatibility offline nor using disc based installs for one very simple reason.

The architecture of the PS3.

Ps4 to ps5 is possible because the architecture of the systems is very close, both using AMD API units, where code needed little tweaks here and there to run as intended.. or better on the new system.

The CELL on PS3 however, is a whole different story and not one that developers really want to look at. To make PS3 games run on PS4, would actually take more development, than getting Xbox games to run on PS4, it's that different.

So Sony were left with 2 options emulation (would be just as tough emulating the CELL on a 1:1 emulation) or cloud based. Sony went for the cloud option. 

Imo they made the right choice.