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Comment by sliken | Hacker News Reader

Yes, you could buy a brand new (announced weeks ago) AMD Turin. 12 channels of DDR5-6000, $11,048 and 320 watts (for the CPU) and get 576GB/sec peak.

Or you could buy a M3 max laptop for $4k, get 10+ hour battery life, have it fit in a thin/light laptop, and still get 546GB/sec. However those are peak numbers. Apple uses longer cache lines (double), large page sizes (quadruple), and a looser memory model. Generally I'd expect nearly every memory bandwidth measure to win on Apple over AMD's turin.

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AnandTech did bandwidth benchmarks for the M1 Max and was only able to utilize about half of it from the CPU, and the GPU used even less in 3D workloads because it wasn't bandwidth limited. It's not all about bandwidth. https://www.anandtech.com/show/17024/apple-m1-max-performanc...

Indeed. RIP Anandtech. I've seen bandwidth tests since then that showed similar for newer generations, but not the m4. Not sure if the common LLM tools on mac can use CPU (vector instructions), AMX, and Neural engine in parallel to make use of the full bandwidth.

You lose out on things like expandability (more storage, more PCIe lanes) and repairability though. You are also (on M4 for probably a few years) compelled to use macOS, for better or worse.

There are, in my experience, professionals who want to use the best tools someone else builds for them, and professionals who want to keep iterating on their tools to make them the best they can be. It's the difference between, say, a violin and a Eurorack. Neither's better or worse, they're just different kinds of tools.

Agreed.

I was sorely tempted by the Mac studio, but ended up with a 96GB ram Ryzen 7900 (12 core) + Radeon 7800 XT (16GB vram). It was a fraction of the price and easy to add storage. The Mac M2 studio was tempting, but wasn't refreshed for the M3 generation. It really bothered me that the storage was A) expensive, B) proprietary, C) tightly controlled, and D) you can't boot without internal storage.

Even moving storage between Apple studios can be iffy. Would I be able to replace the storage if it died in 5 years? Or expand it?

As tempting as the size, efficiency, and bandwidth were I just couldn't justify top $ without knowing how long it would be useful. Sad they just didn't add two NVMe ports or make some kind of raw storage (NVMe flash, but without the smarts).

> Even moving storage between Apple studios can be iffy.

This was really driven home to me by my recent purchase of an Optane 905p, a drive that is both very fast and has an MTBF measured in the hundreds of years. Short of a power surge or (in California) an earthquake, it's not going to die in my lifetime -- why should I not keep using it for a long time?

Many kinds of professionals are completely fine with having their Optanes and what not only be plugged in externally, though, even though it may mean their boot drive will likely die at some point. That's completely okay I think.

I doubt you'll get 10+ hours on battery if you utilize it at max. I don't even know if it can really sustain the maximum load for more than a couple of minutes because of thermal or some other limits.

The 14" MBP has a 72 watt-hour battery and the 16" has a 100 watt-hour battery.

At full tilt an M3 Max will consume 50 to 75 watts, meaning you get 1 to 2 hours of runtime at best, if you use the thing full tilt.

That's the thing I find funny about the Apple Silicon MBP craze, sure they are efficient but if you use the thing as a workstation, battery life is still not good enough to really use unplugged.

Most claiming insane battery life are using the thing effectively as an information appliance or a media machine. At this game the PC laptops might not be as efficient but the runtime is not THAT different provided the same battery capacity.

FWIW I ran a quick test of gemma.cpp on M3 Pro with 8 threads. Similar PaliGemma inference speed to an older AMD (Rome or Milan) with 8 threads. But the AMD has more cores than that, and more headroom :)

CXL memory is also a thing.

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