One question is whether there is going to even
be a M4 Ultra as we know it, or a M4 Max/Ultra Studio.
The Ultrafusion interface seems to have disappeared from the M3 Max - whether that is because M3 was a stopgap, or because they've dropped the idea (or shelved it until this
3D chiplet thing is real) we don't know. They've also moved back on the whole 'Jade Chop', 'one die design for the entire Pro range' idea and made the M3 Pro a distinct die rather than a Max with one end 'sliced off'.
There's also talk of whether they might produce a new server-grade chip, which could go in a Mac Pro or
could just be used by Apple for their own services - but would likely have a definite AI focus rather than the media creation focus of the Studio and 2023 Pro.
If the M4 Max will run in a MacBook Pro it will
probably run in a Mini enclosure - in fact, that's probably been true with M1-3 with the Studio really existing because they needed the enclosure & huge heatsink for the Ultra version.
So perhaps we'll just see a M4 Max Mini and a new Mac Pro with the rumoured "server" chip (which might turn out more like the Mac Studio than the 2023 Pro but surely won't start at $2000!)
Apparently, Macs with MAX & ULTRA are the most profitable Macs sold on a per-unit-sale basis.
[my emphasis]
Sure, but they sell in smaller numbers to a less price-sensitive market. In the case of the Ultra, which is only used in the high-end Studio and the Mac Pro, that's a lot of R&D to earn back from what are probably their lowest-selling units. Expecting to charge 2x the price for the Ultra when it doesn't give 2x the value might have been Apple's mistake.
I own an ULTRA and regret it. It's not 2X faster than MAX even though it is 2 MAX chips linked together.
Doubling the number of GPU and CPU cores was
never going to double the real-world performance other than in a few particular cases (half of which are synthetic benchmarks - Geekbench
is 1.9x faster!) Efficient multi-threading is hard, and some applications simply won't use all of the cores. That much is no different from Intel.
Twice the Media Engines & Neural Engines won't help unless your software uses them. For
some users, twice the RAM (& RAM bandwidth) or extra TB ports will make the difference - and the Mac Pro relies on the extra PCIe lanes from the otherwise redundant SSD controller, but doubling everything - including the "economy" CPU cores - is pretty inefficient. Still, if your workflow
can light up all the CPU and GPU cores or make use use of all the Media Engines then the M2 Ultra will still beat the M3 Max.
Even the M3 Max won't help you much if you're not lighting up all of the cores on a M3 Pro. It's better bangs-per-buck than the Ultra partly because of the new core designs and partly because all the extra cores (over the Pro) are performance cores.