What i have a hard time figuring out is why AMD is launching 1 chiplets cpus whiout integrated video, just make a "Vega 5" chip, use it as igp in these CPU using the 2nd chiplet place.
This is still just speculation but
if they're using the same organic package (
edit: or at least the same basic layout, why would they otherwise put that one chiplet in the corner) for all AM4 SKUs (they could alternatively have different packages for different chiplet configurations) then all chiplets must have the same interface and pinout. That would also mean that all chiplets must be the same size (72-80mm² or the size of the "Rome CPU chiplet"). That Vega 5 chiplet using 12nm or 14nm would add something (at least a little bit) to the cost of a SKU but obviously AMD didn't think that it would be a good idea to add IGPs to all of their SKUs. Even Intel is now selling new SKUs with disabled IGPs. We still have very little information of the different variations of this AMD's chiplet design and we just have seen the most basic 8C version with one chiplet and an IO die.
There's one important thing to note, though. That AM4 IO die is big enough to support all cache coherency logic for two chiplets but still it could be used with just one chiplet and with no dummy die for mechanical stability. That really gives AMD more freedom and saves 7nm silicon for lower end SKUs. They could still release some SKU with 4C+4C configuration but they don't have to use two chiplets for most of the 8C parts. Once the yields get higher, this is going to be a huge benefit. I'm hoping that they could do the same with different EPYC and TR SKUs as well and there's no need for dummy dies in there either.
Edit: And to be clear, I'm hoping that 16C TR could use just two chiplets and same could be true for 16C EPYC also. None of us know what the rules for the chiplet configurations are and we'll just have to wait and see. I'll admit, though, that it's more important for high volume (low price) parts (like 6C and 8C models) to save those precious 7nm chiplets than for TRs or EPYCs. Still having 2, 4 and 8 chiplet variations would be desirable.