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ECC RAM on the 2011 Macbook Pro ?
- Thread starter CopperX
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Not sure they even make laptop ECC RAM for laptops. It costs a heap more too, and provides almost nil benefits.
Reliability, I guess ... when having 8GB RAM, I want to the computer to correct if one of those bits were flipped accidentally ...
It'll never happen. You'll probably never see it in your lifetime. And if it did, you could never ever attribute it to an erroneously flipped bit.
Bits don't get flipped accidentally in hardware unless hardware is defective. If you write one thing to memory and it reads differently, then the memory is defective. Period. ECC provides parity to help prevent this from causing a failure or active data corruption, but if you get to the point where the ECC is correcting a write error, then you still need to replace the stick. The system will still need to be taken down and the memory will need to be replaced. At the end of the day, you don't get any benefit, except maybe less crashing when your hardware fails.
Unless you know exactly why you would need something like this, you don't.
That's a good find, although from that article:
That equates to roughly 1 event every 20 000 hours.
If you left your computer running for 24/7, that would take 2.28 years. Hardly a likely event.
That equates to roughly 1 event every 20 000 hours.
If you left your computer running for 24/7, that would take 2.28 years. Hardly a likely event.
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ECC RAM does not exist for notebook (SO-DIMM) type memory, basically because you absolutely, positively do not need it.
or
It would be foolish to argue that ECC RAM is useless, but it really only makes sense for servers under extremely read/write heavy use cases. Your typical end-consumer usage patterns are a lot less demanding on memory hardware, no matter how important you feel they must be
It would be foolish to argue that ECC RAM is useless, but it really only makes sense for servers under extremely read/write heavy use cases. Your typical end-consumer usage patterns are a lot less demanding on memory hardware, no matter how important you feel they must be
DDR3 SO-DIMM w/ ECC (registered)
While yes, this is true - there are DDR3 204 pin SO-DIMM form ECC (called SO-RDIMM, SO-CDIMM). These are made for space constrained servers and horribly expensive. You'd probably want to spend the extra money on, I dunno, another MacBook?
Of course, nobody needs it, but kinda geeky cool? (if it was say 15% more for the memory, I'd buy it)
I'm pretty sure these modules will NOT work on the MacBook Pro.
http://http://www.compactpci-systems.com/products/id/?34151
ECC RAM does not exist for notebook (SO-DIMM) type memory, basically because you absolutely, positively do not need it.
While yes, this is true - there are DDR3 204 pin SO-DIMM form ECC (called SO-RDIMM, SO-CDIMM). These are made for space constrained servers and horribly expensive. You'd probably want to spend the extra money on, I dunno, another MacBook?
Of course, nobody needs it, but kinda geeky cool? (if it was say 15% more for the memory, I'd buy it)
I'm pretty sure these modules will NOT work on the MacBook Pro.
http://http://www.compactpci-systems.com/products/id/?34151
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ECC quite useful
I don't know about laptops, but on my Mac Pro desktop I've had to replace 2 memory modules at 2 different times due to ECC errors. These were high-quality memory modules that were replaced for free (both times, including cross-shipping) by the vendor. I've also had to replace Dell memory modules on Dell servers (again under warranty) due to ECC errors. These are presumably due to a combination of manufacturing defect and wear rather than cosmic rays or something like that, but still, in both cases, with ECC turned off there would probably have been bit-errors (some chance the bit error was in the ECC and not the data bits).
Note that the Google paper saw that 12-45% of their servers (depending on platform type) had at least 1 error per year and the median number of errors in machines experiencing at least 1 error ranged from 25 to 611. If not using ECC these would be memory corruptions, possibly with serious consequences, especially if they happened in a disk buffer before data was written to disk.
So I reject the conclusion that ECC is not useful.
I don't know about laptops, but on my Mac Pro desktop I've had to replace 2 memory modules at 2 different times due to ECC errors. These were high-quality memory modules that were replaced for free (both times, including cross-shipping) by the vendor. I've also had to replace Dell memory modules on Dell servers (again under warranty) due to ECC errors. These are presumably due to a combination of manufacturing defect and wear rather than cosmic rays or something like that, but still, in both cases, with ECC turned off there would probably have been bit-errors (some chance the bit error was in the ECC and not the data bits).
Note that the Google paper saw that 12-45% of their servers (depending on platform type) had at least 1 error per year and the median number of errors in machines experiencing at least 1 error ranged from 25 to 611. If not using ECC these would be memory corruptions, possibly with serious consequences, especially if they happened in a disk buffer before data was written to disk.
So I reject the conclusion that ECC is not useful.
This is exactly why people are worried about Apple dropping the Mac Pro, Apple have already dropped their xServe.
For those who wonder why.
Mac Pro is a workstation and can be used for mission critical purposes. Having a Mac Pro do two days of computation and a mistake is made, or financial data getting corrupted or someone's life could depend on the machine is when ECC is required.
This type of feature is what makes a desktop computer different to a workstation. A cheaper iMac or Dell PC may have almost the same horsepower as a Mac Pro. A lot of people will compare the HP or Dell desktops in price, but if you look at the Dell or HP workstations they are in fact the same price as the Mac Pro.
ECC is only useful if you need to know that the code AND DATA the system processes are correct!
There is no more likely an error in the ECC bits than the rest of memory, actually less since there are fewer ECC bits than data bits.
or
It would be foolish to argue that ECC RAM is useless, but it really only makes sense for servers under extremely read/write heavy use cases. Your typical end-consumer usage patterns are a lot less demanding on memory hardware, no matter how important you feel they must be
Memory errors are not specifically related to load (except where the load causes increased temperature).
ECC RAM only does any good if the motherboard and chipset on the motherboard support it. I would be surprised if the logic board in a Mac laptop has ECC support.