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>With all respect to Mark Gurman, I think that "half-sized Mac Pro" is going to be a different product entirely if it ships, with a different branding. Mac Mini Pro?

The ever illusive xMac, aka "the affordable Mac tower"

Somebody once said that that Apple’s business model is charging a very high markup for flash memory (currently it’s $50 per 64 GB to upgrade storage on an iPhone or MacBook). The margin on other parts is also high. The user-upgradeable Mac Pro provides an escape hatch from these expensive upgrades. Therefore the entry price has to be much higher to make up for it. An affordable tower would cannibalize Mac Pro sales by providing businesses with a cost-saving opportunity that’s too good to refuse.

One does not simply create a $2trn business by selling flash memory.

This is good analysis, but there's some other effect I'm unable to put my finger on.

The iPad is at least an order of magnitude better than comparable netbooks (though chromebooks, depending on manufacturer, can be competitive thanks mainly to ChromeOS's reduced footprint). So even though the margins are high, the perceived quality, regardless of raw benchmarks, is still something. It's not just marketing to me to say the marriage of software and hardware is unique. (Gruber's observation about NSObject alloc's being a lot faster on Apple Silicon, for instance).

Now that I think about it, honestly Google is the only other company playing by these rules... ie pixelbook, pixel phone, etc. But they're much earlier in the evolution, and have less upstream control in software (especially since Fuchsia seems to be somewhat lower priority than before, though this is second hand knowledge).

Adjust reference counts on an NSObject, allocating one is mostly just a calloc ;)

That somebody is probable only partially right about a partial business unit within Apple. People tend to buy it for the package deal, not for individual specs. At volume, those are the much more valuable customers than the 'buy a single computer' crowd that often talk about their modifications they want to make.

Exactly - Apple "sells" experience, not parts or specs.

Considering how the M1 SOCs are, the possibility of a future "affordable Mac tower" looks more remote than ever. Apple seems to be aiming towards piling as much into their dedicated SOCs as they can. I expect what "pro" capabilities they do build for it going to be in the vein of the cool stuff they were doing in the Mac Pro, like the FPGA "Afterburner" and will probably cost way more than any person with generally "consumer-level" use-cases would want to spend.

As a technology enthusiast I'm excited to see what bonkers stuff they'll be announcing. But, since I am not doing climate models or rendering hollywood movies, I don't expect I will never work on any of them since I don't want to drop a new car's worth of money on one.

The "Mac" is what I want.

> There's nothing about a unified memory architecture that requires the GPU and CPU to be on the same die, let alone requires the RAM to be in the same package

No, but unified memory does require starving the GPU of bandwidth. There's a reason high end GPUs use different types of memory than CPUs.

Either Apple will be content with Mac Pro not having the absolute graphics performance lead, or they will make a discrete GPU with dedicated memory. I'm not sure which they will choose but I suspect the latter.

I agree, i'd also expect more integration of the Afterburner tech with support for multiple codecs beyond the current version.

The Xbox Series X (retail price $499) uses a 7nm SOC, where the GPU has 12 TFLOPS of single precision performance. The fastest single GPU Apple sells on the Mac Pro is 14 TFLOPS (with a step-up fee of $2,400!).

There doesn't seem to be any reason why Apple couldn't integrate a 16 TFLOPS GPU on an SOC using a 5nm or better process. The M1 GPU is 2.6 TFLOPS, they can x6 or more it, and obviously change the memory subsystem (HBM?).

Xbox Series X is very far from the top graphics available. GTX 3090 at 35 TFLOPS is what Apple needs to compete with for Mac Pro. Those chips are reticle limited which means there's simply no room to add a CPU, let alone 32 cores. You need separate dies.

Also, Xbox uses GDDR which trades off CPU performance for GPU performance. Apple probably wouldn't do that for a Mac Pro. The high end needs separate memory so the GPU can have bandwidth and the CPU can have low latency.

Well, depends. If they're looking to replace the low- and medium end of the Mac Pro offerings, a SOC would be fine. If they are looking to exceed it in every way, then a separate GPU with 16x the current M1 GPU cores is necessary. (The GPU on M1 takes up about 30mm2-40mm2). Put that on a TSMC N5P process, and that will be quite the setup...

Reticle limited on Samsung 8nm means plenty of room is available on TSMC 5nm.

Also, GDDR does not have appreciably higher latencies than DDR memory when measured in nanoseconds. It's just more expensive than DDR and much more limited in terms of capacity.

If Apple does go the "huge SoC" route I'd expect to see HBM2 memory with socketed DDR4 or DDR5. It'd provide the best of both worlds - extremely high bandwidth and low latency for a small portion (say 32-64GB) of the memory, and high capacity for the rest (say 1-2TB), all without compromising the unified memory concept.

This is not without precedent - recent Xeon Phis, for all their other shortcomings, have had a similar memory hierarchy.

Yeah but when discrete GPUs get to 5nm they will still be reticle limited. They're not going to stop getting bigger. If Apple maintains a process node advantage maybe they could do SoCs to compete with discrete graphics at the previous node but I think Nvidia will catch up.

I agree that a combination of HBM and DDR sounds pretty good for a unified memory architecture. Are you imagining it as just another layer in the cache hierarchy or something actively managed?

How is it a unified memory architecture if one part is faster than another? Sounds rather non-unified.

"Unified" in this case refers to the CPU and GPU having the same access to memory. This could still be true even if part of the memory is faster, as long as it's faster for both CPU and GPU.

Is there any reason the Mac Pro couldn't or shouldn't combine an SoC with upgradable components?

So you get a certain baseline level of specs, but also have the opportunity to tack on a beefier GPU (which may or may not use UMA), additional slower memory, additional slower storage, maybe even additional CPUs, etc.

> Is there any reason the Mac Pro couldn't or shouldn't combine an SoC with upgradable components?

I don't think so, with the asterisk that I don't know enough to say whether mixing higher-speed and lower-speed RAM is really feasible in that scenario. (IIRC, if you do that in computers now, all the RAM will operate at the lowest speed.)

> if you do that in computers now, all the RAM will operate at the lowest speed

That’s correct, but irrelevant in this context. In that scenario, the memory is all on the same memory controller, and the memory controller used wants to run a single speed, so it has to be the highest universally supported speed.

Apple could have multiple tiers of memory with different characteristics, but just because you can, doesn’t mean you should. I don’t have access to such a test bed, so I can’t speak to what the experience would be like.