Apple discontinues the Mac Pro • Hacker News Board

Re: Apple discontinues the Mac Pro

#641

Post by giwook » Sat, Mar 28, 2026, 4:16 PM UTC

sgc wrote: post #556

x______________ wrote: post #546

Earlier quoted context omitted.

Agreed. Unless you have full control over the production chain to fully produce a device, you are subject to the whims and desires of those who preside over such technological feats that we take for granted in our daily lives. To the original point, it's safe to say that highlighting a nationality with regards to trust is baseless and without merit, as would be for any other topic (men/women from x are y, z food is b…

Rather than people being wary of Chinese in general, it's more that there is a high degree of government control exercised in China and they are known to be very strategic with long-term planning in regards to technology control both for spying and actual remote control of devices. We are all just looking for the least bad option. It's not like devices from other countries are immune, but they are often less organize…

Yes, this is really what I was referring to. And the fact that the original comment I was replying to mentioned "modded Chinese hardware" from some unspecified, unvetted 3rd party which doesn't exactly fill me with confidence.

Re: Apple discontinues the Mac Pro

#642

Post by chirau » Sat, Mar 28, 2026, 4:58 PM UTC

sib wrote: post #587

chirau wrote: post #527

Earlier quoted context omitted.

I live in America, I am very well compensated. Have been for 15 years now. $3500 is a lot of money. A lot. There is a tiny bubble of us tech folks who think it is accessible to most people. It is not. It is also the same reason Macs are still a niche. Don't take your circles to be the standard, it is very very far from it, especially if you think $3500 is not a lot of money. It is easy to confirm this, just look at t…

There are something like 24 million millionaires in the United States... Estimates are that Americans spent $157 billion on pets in 2025. There are a lot of people who could easily choose to spend $3,500 on a computer.

There is no Apple device priced above $3k that has done 1 million in annual sales. The US population is >300M. <0.3% of the population. Don't take your bubble to be representative of society. $3500 is a lot of money, even in the US.

Re: Apple discontinues the Mac Pro

#643

Post by AnthonyMouse » Sat, Mar 28, 2026, 5:31 PM UTC

foldr wrote: post #638

AnthonyMouse wrote: post #589

Earlier quoted context omitted.

Systems with socketed RAM have had on-die memory controllers for more than two decades. CAMM2 supports the same speeds as Apple is using in the M5.

CAMM2 most likely wouldn't work for the Max and Ultra chips: https://news.ycombinator.com/item?id=43266848 https://news.ycombinator.com/item?id=43267075

The logic of those posts is questionable.

The premise of the connector is that it attaches to the board in a similar way as soldering the chips (the LPCAMM connection interface is directly on the back of the chips) but uses compression instead of solder to make the electrical connection, so the traces are basically the same length but the modules can be replaced without soldering. There is no reason you couldn't use two modules to get a 256-bit memory bus. It sounds like AMD designed Strix Halo to assume soldered memory and then when Framework asked if it could use CAMM2 with no modifications to the chip, the answer was yes but not at the full speed of the CAMM2 spec.

CAMM2 supports LPDDR5X-9600, which is the same speed Apple uses in the newest machines:

https://www.micron.com/content/dam/micron/global/public/docu...

The Max chips have a 512-bit memory bus. That's the one where the comment you linked suggests putting one module on each side of the chip as being fine, and there is no M4 Ultra or M5 Ultra so they could be using LPCAMM2 for their entire current lineup. The M3 Ultra had a 1024-bit memory bus, which is a little nuts, but it's also a desktop-only chip and then you don't have to be fighting with the trace lengths for LPDDR5 because you could just use ordinary DDR5 RDIMMs.

Re: Apple discontinues the Mac Pro

#644

Post by foldr » Sat, Mar 28, 2026, 5:37 PM UTC

AnthonyMouse wrote: post #643

foldr wrote: post #638

Earlier quoted context omitted.

CAMM2 most likely wouldn't work for the Max and Ultra chips: https://news.ycombinator.com/item?id=43266848 https://news.ycombinator.com/item?id=43267075

The logic of those posts is questionable. The premise of the connector is that it attaches to the board in a similar way as soldering the chips (the LPCAMM connection interface is directly on the back of the chips) but uses compression instead of solder to make the electrical connection, so the traces are basically the same length but the modules can be replaced without soldering. There is no reason you couldn't use…

> but uses compression instead of solder to make the electrical connection

This is still going to have higher parasitic resistance and capacitance than a soldered connection. That's why it's not just a drop-in replacement for soldered RAM. You'd either have to use more power or run the RAM slower.

> one module on each side of the chip as being fine.

It's fine if you've got space to spare. It's not very practical for a laptop form factor.

>but it's also a desktop-only chip and then you don't have to be fighting with the trace lengths for LPDDR5 because you could just use ordinary DDR5 DIMMs.

Given how few desktops Apple sells compared to laptops, I seriously doubt that they'd want to use a completely different memory configuration just for their desktop systems.

Re: Apple discontinues the Mac Pro

#645

Post by angoragoats » Sat, Mar 28, 2026, 5:48 PM UTC

lowbloodsugar wrote: post #628

angoragoats wrote: post #616

Earlier quoted context omitted.

The machine I’m describing works just fine on a dedicated 15A 120V circuit.

5x3090 in 1600W?

1800W is the max on a 15A circuit, but yes, it’s usually under 1600W. For LLM inference, limiting the TDP to 225W or so per card saves a lot of power, for a 5% drop in performance.

Re: Apple discontinues the Mac Pro

#646

Post by AnthonyMouse » Sat, Mar 28, 2026, 6:25 PM UTC

foldr wrote: post #644

AnthonyMouse wrote: post #643

Earlier quoted context omitted.

The logic of those posts is questionable. The premise of the connector is that it attaches to the board in a similar way as soldering the chips (the LPCAMM connection interface is directly on the back of the chips) but uses compression instead of solder to make the electrical connection, so the traces are basically the same length but the modules can be replaced without soldering. There is no reason you couldn't use…

> but uses compression instead of solder to make the electrical connection This is still going to have higher parasitic resistance and capacitance than a soldered connection. That's why it's not just a drop-in replacement for soldered RAM. You'd either have to use more power or run the RAM slower. > one module on each side of the chip as being fine. It's fine if you've got space to spare. It's not very practical for…

> This is still going to have higher parasitic resistance and capacitance than a soldered connection. That's why it's not just a drop-in replacement for soldered RAM. You'd either have to use more power or run the RAM slower.

This isn't accurate. A compression interface can have the same resistance as a soldered connection.

There is a small infelicity with DDR5 because the DDR5 spec was finalized before the CAMM2 spec and the routing on the chips isn't optimal for it, so for DDR5 CAMM2 requires slightly tighter tolerances to hit 9600 MT/s, which is presumably the trouble they ran into with Strix Halo, but even then it can do it if you design for it from the beginning, and they've fixed it for DDR6.

> It's fine if you've got space to spare. It's not very practical for a laptop form factor.

The modules take up approximately the same amount of space on the board as the chips themselves. It's just a different way of attaching them to it.

> Given how few desktops Apple sells compared to laptops, I seriously doubt that they'd want to use a completely different memory configuration just for their desktop systems.

DDR5 and LPDDR5 are nearly identical, the primary difference is that LPDDR5 has tighter tolerances to allow it to run at the same speeds at a lower voltage/power consumption. When you already have the design that meets the tighter tolerances, relaxing them in the system where you're not worried about 2 watts of battery consumption is making your life easier instead of harder.

Re: Apple discontinues the Mac Pro

#647

Post by washadjeffmad » Sat, Mar 28, 2026, 6:32 PM UTC

spacedcowboy wrote: post #260

washadjeffmad wrote: post #65

Earlier quoted context omitted.

Gaming isn't what people are using Mac Studios for. Thunderbolt also isn't a substitute for OCuLink.

Um, I have an M3 Ultra 512GB on my desk for development. Love me some Baldur’s Gate 3, everything turned up to 11…

I should have said 'buying'. We've all got something fun we run on ours.

Re: Apple discontinues the Mac Pro

#648

Post by washadjeffmad » Sat, Mar 28, 2026, 6:59 PM UTC

rayiner wrote: post #625

angoragoats wrote: post #429

Earlier quoted context omitted.

Maybe; I'm unable to find any benchmarks that specifically compare PCs with TB to Macs to test this. But there is certainly still overhead with TB no matter what, and therefore it'll never be as fast as Oculink.

Sure, but how big of a difference is there? Even inside a desktop PC, you typically have PCIe ports directly off the CPU and ones off the chipset, and the latency for the latter is double. But the difference is immaterial in practice.

I think latency is the wrong focal point (more important for gaming, plus Macs don't support eGPUs anymore). There aren't a lot of general workloads that require high sustained throughput, but the ones that do can benefit from TB5 scaling.

For instance, if you cluster Mac Studios over TB5 with RDMA, the performance can be pretty stellar. It may not be more cost effective than renting compute for the same tasks, but if you've got (up to) four M3 Ultras with a ton of RAM, you'll be hard pressed to find something similar.

That's still not more ideal than having native alternatives like OCuLink or something that can be networked like QSFP, but it's a fair way to highlight the current design's strengths.

Re: Apple discontinues the Mac Pro

#649

Post by krsw » Sat, Mar 28, 2026, 7:08 PM UTC

giwook wrote: post #407

sippeangelo wrote: post #394

Earlier quoted context omitted.

Some Chinese sources sell modded Nvidia GPUs with extra VRAM. They're quite affordable in comparison to even a Mac Pro.

And how much do you trust Chinese hardware?

At this point I trust them more than US or Israeli tech

Re: Apple discontinues the Mac Pro

#650

Post by foldr » Sat, Mar 28, 2026, 7:30 PM UTC

AnthonyMouse wrote: post #646

foldr wrote: post #644

Earlier quoted context omitted.

> but uses compression instead of solder to make the electrical connection This is still going to have higher parasitic resistance and capacitance than a soldered connection. That's why it's not just a drop-in replacement for soldered RAM. You'd either have to use more power or run the RAM slower. > one module on each side of the chip as being fine. It's fine if you've got space to spare. It's not very practical for…

> This is still going to have higher parasitic resistance and capacitance than a soldered connection. That's why it's not just a drop-in replacement for soldered RAM. You'd either have to use more power or run the RAM slower. This isn't accurate. A compression interface can have the same resistance as a soldered connection. There is a small infelicity with DDR5 because the DDR5 spec was finalized before the CAMM2 spe…

>This isn't accurate. A compression interface can have the same resistance as a soldered connection.

All the information I can find suggests that CAMM2 will have higher parasitic resistance and capacitance than a soldered connection. Do you have a source for this claim?

The issue isn't just reaching a certain speed, but doing it at the same power consumption.

>The modules take up approximately the same amount of space on the board as the chips themselves.

They do take up more space, as anyone can easily check. Modern laptop motherboards can be very small, so this is significant.

>DDR5 and LPDDR5 are nearly identical [...]

What I mean is that Apple isn't going to want to invest any resources in adding the option of external RAM just for the relatively tiny desktop market. It's not that it's technically difficult; it just doesn't make sense from a logistical point of view.