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Apple Silicon Macs can't boot from external drive if internal drive failed

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Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#391

Post by wtallis »

floatboth wrote: post #344
wtallis wrote: post #241

Earlier quoted context omitted.

For laptops, soldered vs socketed DRAM is mostly about power, not performance. But it is true that soldering DRAM makes it possible to reach higher bus speeds than are practical to achieve through a DIMM slot; this is why GPUs don't have upgradable RAM.

Laptops that have soldered RAM (including Apple) do not come with overclocked RAM though. I don't even know of any system with soldered RAM that would let you try pushing the speeds in practice, so this advantage is never leveraged. But we do know how far DIMMs can go. Mainboard memory trace layouts have gotten ridiculously optimized. DDR4-5200 is a totally "normal" XMP spec now, there are even 5400 kits out there I…

> Laptops that have soldered RAM (including Apple) do not come with overclocked RAM though. I don't even know of any system with soldered RAM that would let you try pushing the speeds in practice, so this advantage is never leveraged.

This is unsurprising given what I already pointed out about power being more important than maximizing performance. Sure, you can overclock the memory controller on a desktop platform and with sufficiently expensive DIMMs and probably a bit of an overvolt for the memory controller/uncore you can reach higher bus speeds than any laptop CPU (though still not anywhere near as high as GDDR used with high-end mobile GPUs).

But take a look at the fastest memory speeds available through SODIMM slots vs the speed of LPDDR4x supported by the same CPUs. Within the constraints of laptop power levels and using standard grade memory parts rather than requiring premium binned chips, soldering currently corresponds to a 33% performance advantage.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#392

Post by varispeed »

jaywalk wrote: post #54
varispeed wrote: post #27

Earlier quoted context omitted.

If you can't buy parts from 3rd parties e.g. you can't source chips or connectors etc. on Mouser, then I can't see how this is much different from Apple. Just because manufacturer sells parts themselves (thus avoiding spending money on good repair service), probably won't save you much money considering you will have to spend your own time and make effort to fix it yourself. Nonetheless, any move into more repair fri…

Framework's hardware is entirely open source ( https://github.com/FrameworkComputer/ExpansionCards ) so you can buy parts from any third-party that wants to produce them.

Entirely? That's just for expansions which are essentially USB-C dongles.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#393

Post by magicalhippo »

nightski wrote: post #260
wtallis wrote: post #250

Earlier quoted context omitted.

What drive? What was the end of life behavior you observed? Catastrophic failure, or SMART data showing wearout?

Not the parent but I had this happen to me. It was a top of the line Samsung SSD at the time. Catastrophic failure. Was working fine then one day I rebooted and it never came back. I usually plan for failure of each drive every 2-3 years and buy them on Black Friday. But if that took out my entire 3.5k-4k m1 max laptop I'd be rather disappointed. It's $200 to replace a SSD.

I've had two SSD's fail on, both were "here today, gone tomorrow" type failures without warning.

Granted, been a while, but I do nightly full-disk backups due to the first such experience (so was well prepared for the second).

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#394

Post by magicalhippo »

lamontcg wrote: post #309
radley wrote: post #293

Earlier quoted context omitted.

FWIW, a 4TB SSD with the same speed (7GB/sec) is currently $1200 ($750 more than the 2TB). So Apple's price is decent for the current market. https://www.amazon.com/dp/B08Q54GHTC/ I'm certainly not enthused about being stuck with current market capacities, but at least I don't feel gouged on price.

Yeah but I don't need a 4TB SSD right now. I barely need a 2TB.

At least that extra free space will ensure you have optimal speed (SSD's slow down writes when they close to capacity) and prolong the lifetime of the drive (less write cycles per cell), so it's not for nothing.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#395

Post by raxxorrax »

liminalsunset wrote: post #26

General grumpiness about this particular design decision aside, it appears that since the T2 Macs, the main SSD was being used to store core system firmware. On T2 I think it's BridgeOS that sends the EFI image to the Intel side to boot it, and it does the firmware verification and loading. This setup has a benefit; namely, it is now impossible to brick the system with a bad BIOS/EFI flash, and you'll never need to u…

I think the benefit is marginal since compared to harddrives bios flash memory almost never fails and recovery solutions for a bad update are readily available. So this sounds like a bad excuse again.

I work on embedded systems and even the really cheap memory never fails on quantity of thousands of devices if it isn't regularly written to. I has become extremely reliable. Self-checks are still in place of course.

In any case it should not prevent external booting or if it does Apple should just supply the needed files for sensible restore options.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#397

Post by Isaackane »

Coragerard wrote: post #396

Yeah, I am familiar with all that ASR thing. But people are still not sure if it is perfect or not. It proved to be not as robust as it should be.

You are right. It's useful, but up to some extent. We've used ASR to perform tens of thousands of its clones and it was not up to the mark. At many points, ASR fails simply with no obvious reasons and explanations. I could not figure out what's actual data is important to back up and what not.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#398

Post by pantalaimon »

GhettoComputers wrote: post #105
pantalaimon wrote: post #51

Earlier quoted context omitted.

> People aren’t swapping their 2011 i3 for a 2011 i7 if they care about performance I beg to differ. I swapped my 2011 i5-2500k for a 2012 i7-3770 and it was a nice and cheap upgrade. Used hardware is cheap, there is no reason to not upgrade it all the way.

You’re really depending on your mobo to not blow a cap and using way more energy. A used older ryzen 5 is comparable and much better, and the mobos are current. Even a newer intel F processor isn’t much more the 3770K is way overpriced for its performance.

the 3770 was 30€ on ebay and given the rising TDP numbers on Intels latest desktop platforms, I really doubt it uses any more energy than a recent system.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#400

Post by Remiluke »

Theofelix wrote: post #399

The most complicated thing with Mac OS-made silicon is that if the internal storage is not supported, one cannot externally boot it. And that’s a pity.

Usually, internal storage doesn’t die. But what a user will do if it got damaged. Nothing can be done. Apple has made it clear also. One cannot boot an Apple Silicon Mac if its internal storage is damaged. Apple will surely support "external boot" but it will be more limited and let's see what is on the plate they will offer now.
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