Given the timelines involved with designing and validating new hardware, especially when it involves chip design, we can be very certain that Pi 5 development is quite far along already. I know a Pi employee (jamesh, on the forums) mentioned already ~1 year before the Pi 4 was released that they had a good understanding of what the Pi 5 would be. I'd guess that at this point we're at most ~1.5 years from a Pi 5 release. I would hope to see it already this coming summer, but that may be a bit too optimistic.
Of course, the Pi 4 has still not peaked, since we're still waiting for Pi OS 64-bit, the full KMS video driver and Vulkan support. Personally, though, I believe the Pi 5 will in large part compatible with all the SW development work that's going on now, i.e. they will most likely keep the GPU very similar (at least from an architectural perspective).
It's pretty hard to speculate about what the Pi 5 will look like, but I mostly agree with @george-spiggott. Regarding using A75 cores, power consumption of the Pi 4 is already pretty much at the limit for what's practical when it comes to passive cooling. It's unlikely that they'd increase it further. This makes it challenging to provide a generational performance leap without going down to more dense manufacturing processes (such as 20nm or 16nm). So, I'd expect a process upgrade for the Pi 5. I also believe that at 16nm (and maybe also 20nm?) they will need to make some provisions to be able to keep the 3.3V I/O on the 40-pin header, since the silicon is not 3.3V tolerant. This will add cost and complexity.
My hope for the next Pi is that they're able to alleviate some bottlenecks in the design. It seems like memory bandwidth is lower than it should be, possibly because of internal bus limitations. My guess is that this is one of the reasons the performance of N64 emulation is still quite bad, despite seemingly not being particularly CPU or GPU limited on the Pi 4.
For the complicated option (I have not tried this btw :) get one of those backwards compatible PS3s and make it dual bootable with Linux, run PS2 games on the straight ps os and maybe other emu's on the Linux boot?
:) I see youtube videos of people doing some of that but don't really know if the whole thing is possible. Might be fun to look into though if you have too much time?
edit: and maybe you could try to find an broken PS2 to just use the enclosure, take apart the PS3 and fit it into the PS2 shell. Voila! A PS2 made out of a ps3! :)
EDIT: wow performance is absolute garbage, how can this be, i looked in some forums, and everybody is like "oh you need dual core" dude i have a quad core 3.4 Ghz i7? Is it the settings or is it ubuntu itself?
i was wondering if dreamcast ps2 and gamecube discs need to be dumped to a file for use with retropie pc version, or if they can be read via the dvd/br drives in pcs directly in some of the emulators ?
As far as I know, pcsx2 can read the DVD drive directly, for reicast/dolphin, you'll need a disc image
if they need to be dumped,. i believe dreamcast discs have a different layout than normal cds, can those be dumped with a regular dvd drive ? Or is it so that if someone wants to play these in an emulator he/she has to download official dumps of these discs ? with what program and drive do i need to dump any of dreamcast/ps2/gamecube discs anyway ?
Look around for instructions on how to backup your discs, there are no 'official dumps' provided by the vendor/publisher (though they're plenty 'unofficial' ones). Here are some pointers:
I've been meaning to provide an update for the for a while so here goes.
I still haven't fully resolved the issues with the controllers but I've not really had a good stab at it yet.
A few more photos; generally I'm happy. When reassembled the fan blows straight across the compute module (which was the idea) so adding a heat sink so keep it nice and cool.
The HDMI port in not fully aligned - not a major problem but the perfectionist in me doesn't like it - that on the list of changes if there's ever a next version. Also, I'm not too keen on the empty hole to the right, might be an idea to add another USB port in future.
Front USB port fits nicely into a slightly modified memory card port but doesn't sit at the correct height - something else to be tweaked.
As for the next version, this is on hold for now. One of the original aims for using the Compute Module was future upgradability base on the assumption future Compute Modules would keep the same interface/footprint. The ultimate hope was the come CM4 or CM5 the power might be there for GameCube emulation.
However, I've read that future versions might deviate from the SO-DIMM 200 interface, hence I'll hold off on making any more hardware changes with this until there's more clarity on what the future holds. It's been a fun process and has taught me a lot on the way - which was the real aim anyway!