It'll be interesting to see how this plays out - the chiplet architecture gives AMD a lot of flexibility in doing things like this. As long as Zen4 IF is compatible with Zen3 IF (which it should be), they could just plonk down a Zen4 CCD next to a Zen3-era IOD on a new substrate (so much cheaper than new silicon!) and run the whole thing off socket AM4, as the IOD has all the "communicates with other hardware directly" bits - assuming there aren't some BIOS/other low level motherboard feature things that Zen4 needs to work. Of course, tuning, pricing and value would be ... complicated with this. Do they limit the performance of these chips to not cannibalize AM5 sales? But that would tank value, forcing them to lower prices, which might also cannibalize AM5 sales? Or do they run them at full speed, prioritizing CPU sales over new platform sales? How would that place them competitively vs. Intel, with the platform features disadvantage of AM4? And how would they be priced compared to the closest AM5 equivalent? Lots of interesting questions, it'll will be fun to see how AMD balances all of them. If any of this pans out, of course.
I've mentioned that a lot in other threads - Intel have gone for mixing two different core types together, while AMD went for adding more of the same type.
A combination of the two technologies could let AMD create some incredible hardware - With how Intel made MS patch windows, nothing is stopping 8 Zen4 3Dcache "P" cores as the primary CCX, with 24 Zen3 'E' cores (undervolted for efficiency, like at the 4.5GHz level) in another three CCXs
Do an intel, with some cores for single threaded performance and low ass 3Dcache latency, with more efficient last-gen ones to take over the multi threaded workloads, re-using older parts
Imagine the cost savings of using existing Zen 3 dies in hybrid Zen 4 parts, since they can be also be used in any product in the AM4 stack, with existing stock and a steady supply of parts on mature fab processes?
And then because they've already proven they can re-use an IO-Die between series, that technically could work on AM4 and AM5. (AM4 parts would simply need a 105W-140W limit)
Have they tested this stuff internally? Seems like it.
Will it get released? nobody knows
I'm not sure i worded part of that right, but the idea of AMD making Zen 3 parts for a few more years seems insanely cost effective as a business. Focus on a single 8 core CCX die, and making it as cheap and reliable as possible over time at the fab plants.
They could use them from anything from a 5600x to a Zen 4 hybrid, giving them almost no risk of mass producing them and stockpiling them.
It's not like intel where the E cores are something new, they could use the exact same CCX die on any AM4 or AM5 part they wanted, giving them financial loss if they cancel a product or end AM4 support
Even if theres failed cores on the dies, they can still do 5600x, 5900x or any hybrids that add 6 core CCX's - the cost efficiency is still there and will definitely be cheaper than any Zen4 CCX's, for a few years at least.
