....
But the 7.1 is a different beast, the max amount of RAM and graphic power is way beyond what a SoC may include in quite some years a head.
Years ( or year ) ahead really more so depends upon when Apple started. The lead time on these SoC is about 2-3 years. If they didn't start until wrapping up the 7,1 in 2019 then 2022. If they started in 2018 then late 2021 is plausible.
Since they also need something for the iMac (and Mini for the rest of the line up beside the foothold the i3 variant was holding down ) my guess , is that it was 2019 so 2022 is more likely.
That should free up more "bulk 5nm" wafer starts too as some other chips will be moving on to 3nm around that time.
How will Apple solve this?
Multi SoC solutions? Against the SoC concept, and also less flexible, you get multiples of CPU+GPU+RAM, not just more RAM.
Not just multiples of GPU. But Secure Enclaves . Neural Engines. Separate Image Photo/Video processors . Separate TB controllers and USB hubs . Putting multiple computers inside a single box isn't what the Mac Pro does.
New dedicated CPU with external RAM/GPU? A very costly development for a very limited niche.
Loop in the iMac and it isn't that small. The iMac doesn't cover the PCI-e lane count that the Xeon W 3200 series does ( x16 versus x64 ) , but at least gets them on the path to some other volume part that actually tries to provision mild double digit numbers of PCI-e lanes.
In fact this "half height" Mac Pro (with lots less slots ) is even closer to what the iMac 27" would probably need.
SoC with additional external GPU/RAM? Against the SoC concept, probably lots of dead weight on the SoC.
I doesn't really conflict with the SoC concept at all if get out of the whole there can be one and only one GPU mindset. SoC is more so about collapsing stuff that was on previous mother logic boards into a single package ( and as a single die if can get away with it). A more integrated circiut. The SoC just need to collapse 'some' other chips to get more integrated.
Apple doesn't have to build a GPU that does everything for everybody.
For example the MBP 16" has two GPUs. So does the iMac. Apple wants to completely own the iGPU space. That's fine but that doesn't drop out the requirements for things like:
40-100GbE ( Network SAN enabling cards )
U.2 drive card (new at Sonnet
https://www.sonnettech.com/product/fusion-dual-u2-ssd/overview.html ) or just quad M.2
DAW audio cards
....
all of which were not on the main logic board in the first place.
Apple can put a Thunderbolt controller in the SoC but that won't cover everything. But it does collapse some of the discrete chips in the current Mac Pro 2019 (7,1) onto the SoC. Similar candidates are the PCI-e switches ( the big PEX or at least some of the smaller ones ). Those too could be collapsed into the SoC . And some synergy to that too because in one driver for those is the Thunderbolt controllers (built into the system).
There is a substantial amount of complexity of the 7,1 mainboard that Apple could take out of 3rd party components and push into the SoC.
A larger iGPU on a "big" Mac Pro SoC isn't dead weight if that is where the unmodified iPhone apps run. Nor if ML/GPU computational work is handed too it.
The M1 probably isn't all that big die wise. Probably in the 110-130mm die range. Apple could grow up to 300mm and still not be "super huge" but could add 2-3x P cores and/or a 2-3x GPU. Doesn't technically have to be one die either and still land in the Unified Memory zone with one big RAM pool.
Go for a less capable/expandable Pro machine, with a high-end SoC. Maybe some limited expansion slots.
That seems to be the track they are on with the recent "half" sized Mac Pro rumor. But it remains to be seen if they are going to stop there.
The 7.1, with new MPX and afterburner cards, looked like a future proof safe bet for a new line of Pro machines lasting several model generations. Since that development went parallel to that of the ARM transition you would hope for some "plan", or?
There is little about Afterburner that seems a "dead end". Apple is pointing more so at the ML/Neural and M-series image processor workloads at more standardized formats ( either tweaks on uncompressed state or compression/decompression to standard formats. Probably Apple's new ProRAW stuff ). But high workload ProRes still looks to be covered by Afterburner still . Thunderbolt doesn't really "enable" ProRes. Apple has gobs of other competing function units competing for transistor budget inside the SoC so the image compute function probably isn't going to pick up "fixed function" ProRes any time soon.
MPX ... same issue of whether or not believe Apple is going to build "everything for everybody" GPUs or just stick with "king of the iGPUs." If they need to hook DisplayPort out back into the switch matrix to feed back out the standard ports then it is probably still there. Apple is also probably highly committed to the elimination of internal wires 'dangling' around inside the box looking less 'clean'.
Even if Apple cuts the number of MPX bays in half, it is probably still going to be around because the root cause issues are still going to be there.
Maybe the 7.1 team had rather little knowledge about the other development, and just went all in? Maybe we have an overengineered fantastic machine, but also a dead end, just like the incredible Macintosh IIfx?
I think what is lost is folks who expected Apple to chase the mainstream Threadripper, EYPC , Xeon SP workstation models on features. That isn't going to happen. The Mac Pro isn't going to be kind of the main application core count ( > 28 cores and shooting for triple digits ). That isn't going to happen.
Apple is extremely unlikely their single threaded performance for "more cores". Nor throw the ML/Neural cores out the window to crank P core counts. The next Mac Pro system(s) will probably have very hefty transistor budgets thrown at some somewhat narrow computational areas. Way , way , way more than what the path of Threadripper, EYPC, and Xeon SP are likely going to be.
Whether the quad digit GB of RAM capacity also disappears is unclear. that may be on the chopping block along with "absolute maximum core count" mindset.
The "full sizs" , 8 slot Mac Pro might take longer than the 2 year transition that Apple set out. [ Apple will claim transition completeness 'victory' with just the "half size" Mac Pro ] And it probably won't be iterated on at the same pace as the rest of the line up. Apple doing a "M-series biggest " ( M1Z ? (if 3 or 4 total ) ) may only come once every 4 years or so. And it won't be much cheaper.
It probably depends upon how many Mac Pro 7,1 they sell and how much they want to keep a "iMac Pro" like product around. ( or just let the iMac consume that relative performance space).
