Hacker News

points by bigwheels 2 days ago | 0 comments

> With 16GB of unified memory standard, configurable up to 32GB, and higher memory bandwidth up to 170GB/s

Apple MacBook M5 Max has bandwidth up to 600GB/s, is 170GB/s for M6 the real limit? If so, wouldn't this slow down LLM processing?

[–] Choco31415 2 days ago

There are rumors that Apple is not releasing Pro/Max versions of the M6 with the intention of focusing these research efforts on the M7 instead.

Even then, 170GB/s is a bump up from 153GB/s of the M5. So we see a 11% uplift already.

[–] brandon272 2 days ago

> So we see a 11% uplift already.

Am I crazy, or are a lot more people using the term "uplift" in place of "increase" within the last year? Google Trends (for whatever it's worth) shows a significant increase (uplift?) since mid-late 2025. [0]

[0] https://trends.google.com/explore?q=uplift&date=today%205-y&...

[–] reaperducer 2 days ago

It's monkey-see-monkey-do language.

See also: The use of "learnings" instead of "lessons."

[–] desolate_muffin 2 days ago

that one and "educator" both make my skin crawl for some reason

[–] jemmyw 2 days ago

Language changes. People at work have started saying things are an easy lift instead of a quick win. And it's not new hires, it's the people I've worked with for years. I never got on board with quick win either.

Some people adopt stuff faster than others. I've lived in NZ for nearly 20 years and called someone bro for the first time just last week while playing a sport "should have left it for me bro". Slipped out natural as. Still having bad thoughts about it.

[–] ok_dad 2 days ago

Shit I still use “low hanging fruit”! How out of date am I?

[–] mgiampapa 2 days ago

Here I am doing the needful still.

[–] Implicated 2 days ago

> Even then, 170GB/s is a bump up from 153GB/s of the M5. So we see a 11% uplift already.

My M2 Pro does 200GB/s.

wtf are we even talking about here.

[–] bdcravens 2 days ago

I believe they're discussing the base processors as a way of comparing generations, since there is no M6 Pro/Max. (the M2 base was at 100GB/s)

For a direct comparison to your processor, the M5 Pro is at 308GB/s.

[–] hbn 2 days ago

Why are we comparing the M6 to the M5 Max?

What was the speed of the base M5?

[–] onion2k 1 day ago

Why are we comparing the M6 to the M5 Max?

Because the question is "Which is better for local inference out of the M6 or the M5 Max?"

If an M6 Pro/Max was an option that would change the question.

[–] bdcravens 2 days ago

As pointed out in a sibling comment, 153GB/s.

[–] gaoshan 2 days ago

If you want to do anything beyond getting a small single-core speed bump the M5 Pro is a better, more capable purchase. At least until the M7 comes out.

[–] brandall10 2 days ago

It's a base M6 chip. The Pro doubles that, and the Max doubles again. And the Ultra doubles yet again. This is how the entire M series has always worked.

So the theoretical Max would be 680GB/s.

[–] epistasis 2 days ago

The M6 version is also cheaper than the M5 Max by a significant amount. I wouldn't be surprised if the M6 could keep up on LLM prefill (compute bound), but the memory bandwidth means that decode is going to be a lot slower, most likely?

[–] booty 2 days ago

It's also absolutely wild that you apparently cannot spec one with more than 32GB, for any amount of money? Wow.

Not that I blame Apple here, for once. Seems like they're trying to cope with the limited quantity of RAM they can procure. And with the paltry bandwidth (170GB/s) of these CPUs they're a bad choice for anything but tiny local models anyway.

[–] Schiendelman 2 days ago

That's for the base model M6. The Pro can take more, the Max even more, the Ultra the most.

They're not making those models for the M6 though; they rerouted their resources to making M7 faster at running local LLMs.

If you want more bandwidth, get an M5 Pro, Max, or Ultra. If you want a lower power base model, get the M6. If you want to have your cake and eat it too, wait for the M7, reportedly in the spring.

[–] dannyw 2 days ago

Umm yes, the M6 chip only has a certain amount of memory controllers and channels, which means you can only have so many LPDDR5X modules.

Yes, high-capacity LPDDR5X are made and do exist, but for all practical intents and purposes, you can't buy enough of them to deliver to customers at Apple scale.