Yesterday, Sony released a very detailed guide on PS5 backwards compatibility. Generally speaking, that's very good news, with only a handful of PS4 games confirmed to be non-compatible.

But even in the good news, a handful of demons lurked in the details. One example is game streaming: just as the PS4 can stream games to the PS Vita, the PS4 will be able to stream games to the PS5.

As Sony points out, the advantage of using remote play in this way is that the precious SSD space (rumored to be only 664 GB when the OS is taken into account) does not have to be used for PS4 games.

However, there is a downside to this as well: while PS4 games played on the PS5 will generally get a boost in performance, games streamed from the PS4 will be the same as before, minus the delay that a home Internet connection adds to the mix.

This is not surprising, which is why things like Google Stadia and Microsoft's Project xCloud will theoretically work on basically anything with a screen, from the best Chromebooks to the best cheap phones. In this example, the PS4 is the server and the PS5 does the relatively simple task of displaying the stream on the screen.

Therefore, streaming PS4 games to the PS5, while an interesting party trick, is unlikely to be used in practice; it would be a waste to power two devices in the same house when only one console could provide the same performance or better. Furthermore, since you have to keep the PS4 to stream games on the PS5 anyway, why not just play natively if the performance is the same?

Solid state drives may be expensive, but if backward compatibility on the PS5 proves to be as robust as Sony suggests, most people would be better off trading in their PS4 and spending the money on SSD expansion for a PS5 instead.