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Memory / CPU testing
- Thread starter MaxBurn
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I read something a week or so ago that I can’t find now, believe Firefox, they decided to implement a very basic memory test to run and submit along with bug submissions. Turns out there’s a good amount of bad memory out there, region of 15~20% of their bug reports.
I’m not having any trouble but I know how subtle and easy to miss that can be, and I like to know while I’m under warranty. I ran the built in diagnostics and I’m not reassured by a couple minute test. Once you’ve seen a machine fail 40 minutes into memtest86 like I have I’d rather have my trust earned.
I’m not having any trouble but I know how subtle and easy to miss that can be, and I like to know while I’m under warranty. I ran the built in diagnostics and I’m not reassured by a couple minute test. Once you’ve seen a machine fail 40 minutes into memtest86 like I have I’d rather have my trust earned.
Presumably, it would be the cause of bug reports in other apps, and the OS itself?
Apple's RAM does have some kind of error correction: LPDDR5 has on-die error correction; and Apple has patents related to ECC, which suggests that it's involved in the SoC.
Apple's RAM does have some kind of error correction: LPDDR5 has on-die error correction; and Apple has patents related to ECC, which suggests that it's involved in the SoC.
That follows and it's likely a small but significant ammount.
That I did not know, do even the macbook air's have this? I need to do a little research here it seems.
EDIT; seems none of the mobile macs have ECC. Did find out that mine has unified memory and a much lower need for ECC though. Interesting.
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LPDDR5 and DDR5 have a type of error-correction built-in, but it's not the same thing as what people think of when they say "ECC"-memory.
Where did you find this? Surely it's all the same M-chip, whether it's in an MBA or a Mini....?
Unified Memory just means there's no duplication between the CPU and GPU.
Yes, the standard DDR5 error-correction isn't the same as ECC memory on a Xeon CPU; but Apple have certainly done their own stuff on the chip, based on their patents.
You answered your first paragraph with your third paragraph, that's all. Now if it has some form of memory correction that's great.
Unified memory also puts everything together within one little package, much less chance of corruption from external things, least that was the theory I was reading about.
It isn't even the same chip within the 25' 13" MBA, different core counts. I'm kind of thinking that's due to binning though, probably same thing with couple cores disabled on the lower models so the features would presumably be the same.
Unified memory also puts everything together within one little package, much less chance of corruption from external things, least that was the theory I was reading about.
It isn't even the same chip within the 25' 13" MBA, different core counts. I'm kind of thinking that's due to binning though, probably same thing with couple cores disabled on the lower models so the features would presumably be the same.
I am not aware of any memory testing tools for Apple Silicon Macs. Apple themselves are fairly quiet about these things. That said, they published a lot of patents over the last couple of years pertaining to testing and even correcting LPDDR5 memory, so it’s possible that some of this stuff is already built into the system.
maflynn
macrumors Broadwell
Have you tried the Mac App Store?
I searched for "ram test", and it showed multiple relevant results. I have no idea about the quality of any of them.
The Blackmagic disk test came up, and I've seen its disk-speed results posted a fair amount. I have no idea if it includes a RAM test, or whether that's just the App Store search algorithm being fuzzy. The Amorphous test also came up. That's another name I've seen posted in benchmark test results.
The search terms "memory test" didn't work. The results were all human-memory games, challenges, exercises, etc.
If you want to "burn in" your machine, i.e. run it hot and see what happens, do this in Terminal:
Paste that into a Terminal window a few times and it should get pretty warm pretty quickly.
To terminate all of them:
I searched for "ram test", and it showed multiple relevant results. I have no idea about the quality of any of them.
The Blackmagic disk test came up, and I've seen its disk-speed results posted a fair amount. I have no idea if it includes a RAM test, or whether that's just the App Store search algorithm being fuzzy. The Amorphous test also came up. That's another name I've seen posted in benchmark test results.
The search terms "memory test" didn't work. The results were all human-memory games, challenges, exercises, etc.
If you want to "burn in" your machine, i.e. run it hot and see what happens, do this in Terminal:
Code:
yes >/dev/null &To terminate all of them:
killall yes
MacCheetah3
macrumors 68030
Unless you are witnessing stability problems, I don’t see it as a necessity. Nonetheless, if you are very strongly compelled:
www.micromat.com
Folding@home (or similar) will prove reliability more than most “synthetic” tools. It’s a variable, generally high-demand workload that requires precision and integrity.
I guess, too bad there isn’t a Mac equivalent to OCBASE/OCCT.
apps.apple.com
Techtool Pro 21
Techtool Pro is Mac utility software for maintaining and troubleshooting your Mac, including drive repair, RAM testing, and more.
www.micromat.com
Folding@home (or similar) will prove reliability more than most “synthetic” tools. It’s a variable, generally high-demand workload that requires precision and integrity.
I guess, too bad there isn’t a Mac equivalent to OCBASE/OCCT.
Alternatively:
Endurance: CPU Stress Test App - App Store
Download Endurance: CPU Stress Test by Tunabelly Software Inc. on the App Store. See screenshots, ratings and reviews, user tips, and more apps like Endurance:…
apps.apple.com
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Basic75
macrumors 68030
Apple puts the unified memory on the package, but that's not what makes it "unified". An Amiga 500 with only Chip-RAM had unified memory that was not on the CPU package.
Basic75
macrumors 68030
dmccloud
macrumors 68040
ECC Ram (such as is used in servers and AMD Threadripper systems) contain extra chips on each stick of RAM to handle error checking. The type of error correction done on Apple Silicon does not use separate chips for parity/error correction. What can cause RAM errors is RF interference with the lines carrying data between the CPU and RAM. Since Apple Silicon has the RAM on the same die as the CPU, the data paths are significantly shorter and less prone to that type of interference. Unified RAM simply means that the CPU and GPU can access the same data in RAM simultaneously instead of having to copy data to both the CPU and GPU RAM partitions and reconciling changes after the fact.
Basic75
macrumors 68030
No, it doesn't, as several messages in this thread already said, it's on the same package, not on the same die.
MacCheetah3
macrumors 68030
@MaxBurn
Prequel:
www.level1techs.com
LPDDR5X does support direct link ECC (DLEP). It’s unconfirmed if Apple is using such.
www.micron.com
Either way, (much) shorter traces and the ultimate lower power draw, also reducing the DRAM heat — yes, I know the SOC radiates heat that can at least somewhat affect surrounding components — are still (stability/reliability) advantages.
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LPDDR5X does support direct link ECC (DLEP). It’s unconfirmed if Apple is using such.
LPDDR5X with enhanced ECC for automotive rises to the challenge
Micron Technology has been the global leader in memory and storage solutions in the automotive market for over 30 years. This success builds on our innovation and close collaboration with the ecosystem of automotive SoC vendors, OEMs and tier 1 suppliers.
www.micron.com
Either way, (much) shorter traces and the ultimate lower power draw, also reducing the DRAM heat — yes, I know the SOC radiates heat that can at least somewhat affect surrounding components — are still (stability/reliability) advantages.