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View Full Version : What does "ECC" and "Non-ECC" mean (RAM)


thomasp
Nov 20, 2005, 04:34 AM
Firstly, sorry if this is in the wrong forum - mods feel free to move it :)


I've noticed when looking on the Apple store at computers (especially the new G5's), and when looking at PB RAM, there's often either "ECC" (not so much with the PBs) and "Non-ECC" after the RAM name.

What does this mean?

Also, on the Apple Store, ECC RAM seems about £100 more expensive per Gb than Non-ECC RAM...

:confused:

Kernow
Nov 20, 2005, 04:46 AM
It is to do with error correction. If you absolutely need to guarantee no errors in any calculations you do, then you should use EEC memory - this is why it is more expensive.

See the previous thread about this - http://forums.macrumors.com/showthread.php?t=157322&highlight=eec

Chundles
Nov 20, 2005, 04:50 AM
ECC = Error Correcting Code

It means that for high priority workstations and servers that random bit flips don't screw up the final result.

The original PowerMac G5 cluster at Virginia was only a proof-of-concept supercomputer cluster because the PowerMacs didn't use ECC RAM at the time. The PowerMacs were used to demonstrate the viability of Mac OS X as a server OS and were sold cheaply online when the xServe was introduced which could use ECC RAM.

thomasp
Nov 20, 2005, 07:08 AM
So for normal, everyday use, is Non-ECC RAM OK?

Chundles
Nov 20, 2005, 07:23 AM
So for normal, everyday use, is Non-ECC RAM OK?

Unless you count "normal everyday use" as rocket science, long range weather prediction or complex molecular modeling you should be right with the regular stuff.

ECC RAM is really an option that has been added to make the PowerMac look more professional and "super-computer like" than it was before. It's for the big time mathematics like computing load distribution on aeroplane wings and stuff like that.

cube
Nov 20, 2005, 07:24 AM
It means that for high priority workstations and servers that random bit flips don't screw up the final result.


A bit error can also result in a computer crash.



BTW, EEC = European Economic Community

Chundles
Nov 20, 2005, 08:39 AM
A bit error can also result in a computer crash.



BTW, EEC = European Economic Community

Yeah, that too...

thomasp
Nov 20, 2005, 03:45 PM
BTW, EEC = European Economic Community

Yeah, I kind of noticed that shortly after posting this thread, and didn't bother going back to edit it, because the original title would have remained :) :o

Nermal
Nov 20, 2005, 03:59 PM
I've fixed it for you :)

thomasp
Nov 21, 2005, 02:37 AM
I've fixed it for you :)

Thanks :)


And thanks for the help, everyone else :D