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Discussion in 'Mac Basics and Help' started by MrAndersen, Mar 7, 2006.
What the heck does that mean, what's the difference and is it worth paying for?
In anything other than servers, go for non ECC. I don't know the exact meaning off the top of my head but it is basically error checking that is redundant in workstations and has a performance and initial cost overhead.
Go for non ECC.
ECC - Error Correcting RAM -- 9 bits per word instead of 8.
Most RAM is non-ECC -- the only machines that need ECC typically are servers and high-end engineering/research workstations. Desktop Macs don't need ECC.
ECC RAM stores an extra 'parity' bit that acts like a checksum on the rest of the word. So if there is a single-bit error in reading from memory, it can automatically recover. (if there are errors on 2 or more bits, you're just as pooched as with non-Error correcting RAM)
As you might guess, ECC RAM is more expensive, and usually extracts a performance hit because it has to do 12% more reading and writing.
ECC protects against random "flips" of data in memory, like those caused by solar flares. Performance is only slightly worse...the extra parity bit is not read by the system, but it is used in a quick "check" that takes a beat every time the memory is read. This might bump up the latency by one cycle.
For some applications, these rare and minor errors could result in a disaster. If your computer was being used for, say, air traffic control or monitoring the electrical grid, a crash or incorrect calculation could mean Really Bad Things. A failure in a server used by a large company (banks, the IRS) could result in a huge business disruption.
But for most individuals, ECC doesn't matter. A single bit flip that occurs while you're playing Warcraft will probably not affect things at all.
Its Error Correcting Code.
Its used in most servers are server for more then lets say 20 people. Our school's servers are all ECC. So I would say if the server is hosting a web page / email/ file server and there is no one to restart it if crashes, Then go for ECC. Its not too much more expensive. But for desktops I would not go for it unless you are doing something like others mentioned.