Apple’s Next Mac Pro Could Be an Ingenious Solution

Apple’s move to Apple Silicon has been hugely successful and the entire lineup has been moved over with one exception:  The Mac Pro.  Replicating The Intel Xeon-class workstation has been more difficult than every other Mac due the unique position of the machine as well as its demanding client base.  A Previous incarnation of the Mac Pro, which featured limited expandability drove a wedge between Apple and its workstation customers and led to a new Mac Pro in 2019 which reverted to the large tower design.  What will we get with the Apple Silicon Mac Pro?  Let’s investigate.

The Current Intel Mac Pro 

The current Mac Pro, introduced in 2019, is in a very unique spot in the lineup .  It’s a huge tower that looks a bit out of time in Apple’s lineup.  There’s a reason for that, Apple tired a second generation Mac Pro in the infamous trashcan configuration with an early version of Thunderbolt as its only expansion options.  It did not go over well to say the least.  It’s form factor and lack of PCI-E expansion was not only unpopular, but it couldn’t cool the hot and power hungry Intel Xeon inside.

With the third and final generation of the Mac Pro, gave Apple customers something nobody thought possible, an innovative tower.  Sure it was expensive, but it gave things never before seen.  The rear I/O was on a PCI-E card and Apple took advantage of a new type of PCI-E card called a MPX module that used a second connector in addition to the x16 PCI to deliver full power and bandwidth to the up to 4-slot MPX card.  The Mac Pro also had plenty of cooling with 3 custom designed fans lording over 3 cooling zones.  Keep both of those in your thoughts, they’ll be important later.

The Intel Mac Pro had an insane amount of ECC- memory expansion, but to one 1.5TB for the most demanding customers and up to 28 cores over 12 dims modules and up to 4 W6800s with twin duo cards or 2 w6900 cards for graphics.  This was a beast of a machine.

What Apple Silicon Can and Cannot Do

While the Mac Pro had its origins in the highest ends of PC workstations, Apple Silicon’s beginning start at the other end of the spectrum: the iPhone.  The M-series chips share Performance, Efficiency, and GPU cores with the A14 (M1) and A15 (M2).  They add a whole lot more cores and on-die codecs similar the Intel Mac Pro’s Afterburner card.  As a result, these very efficient chips have punched well about their weight.

There’s a catch, well, and a cache.  The more cores in the SoC, the more inefficient the design becomes.  In the M1 era this is even worse since there has been some discussion about Apple not including enough cache for the amount of GPU cores.  So far the M1 Ultra, which combines 2 M1 Max chips into one super chip, is the top of the line.  While a powerful consumer chip, it’s not even in the league of the current Mac Pro in GPU power.  That’s a giant problem if the Apple Silicon Mac Pro maxing out with a M2 Ultra are true.

A Possible Ingenious Solution.  

A little more than a week ago, 9to5mac.com found a reference to Compute Module.  This could mean a lot of things from the rumored mixed reality glasses to the possibility of Apple getting into the embedded market to help fund Apple Silicon.  There’s another option that could lead back to the Mac Pro.  Let’s say it's not financially feasible for Apple to release custom X-series Apple Silicon for the Mac Pro and the M-series by themselves aren’t up to the task.  What about a daughter card?  Inspired by the MPX modules in the Mac Pro and the intel NUC modules from a few years ago, these compute modules could give the Mac Pro the ability to change out these modules.  The modules would include all the rear IO.  The case would include storage and front I/O, though the front I/O could include a removable card as well to keep it relevant.

The Mac Studio has less volume than a Mac Pro MPX module, so wouldn’t that be a big empty case?  Also, wouldn’t it run into being just a single M2 Ultra?  That’s where it could get interesting.  What if Apple had an internal interconnect similar to AMD’s infinity fabric that could link multiple of these modules together?  That would make up for the deficiencies in CPU cores, GPU cores, and max RAM.  Since the CPU is in a SOC with the GPU, the Mac Pro case could have up to 3 of these modules if they were quad-height.  Furthermore, there could also be 1 and 2-module cases and even a single module All in one to replace the iMac Pro.  The modules don’t even have to be just the Ultra either.  They can be anywhere from the Pro to the Ultra and maybe even mismatched allowing for the kind of tailored to task customization that has been lacking in Apple Silicon.

While it would not deliver the ECC RAM, same about of RAM, or replaceable RAM, it would be a lot more user upgradable/ replaceable than current Apple Silicon and that could be enough to sway current Mac Pro customers to Apple Silicon instead of Dell or HP workstations.

There’s one more question, why did these compute modules show up in IOS?  Apple has another little-known variant of IOS called bridgeOS.  It was designed to bridge together functions of an Apple Silicon T-series Apple Silicon chip with the intel main processors.  The T2 used in the final Intel Macs was actually a variant of the A10.  There could be a similar chip on the motherboard to bridge the multiple modules together with the functions of the motherboard.

Final Thoughts 

I will end with this disclaimer.  This is all speculation based on available information.  I have no sources, supply chain, or otherwise.  This could be the Mac Pro or it could be something very different.

What’s certain is that comments from Apple executives seem to indicate we’ll find out sooner rather than later.  After Backtracking significantly, I just don’t see them returning to the mistakes of the Trashcan Pro.  I think the Mac Pro will be something out of left field that delivers on the promises to professionals and not just a return to the name.