RAM sticks and parity

[rookie1010]

Hi
do all RAM sticks which offer parity check have 9 banks. i read some place that for 8 bit word, onebit is issued from each bank and the parity is issued fro mthe ninth bank. is that true?

 

[CrucialLabs]

Yes, that is correct. All ECC memory will have 9 chips on the module and will add an additional bit for error correction.

 

[rookie1010]

so for a 8+1 byte , each bit of the byte comes rom a differnt physial chip?

 

[CrucialLabs]

Each chip is providing 8 bits of information and for 8 chips at 8 bit is your 64bit data path. The 9th chip is also providing 8 bits of data to check errors so yes the information is coming from each chip. The old parity technology was to add one bit to the end of each 8 bits, the new technology places 8 more bits at the end of the 8 sets of bits.

Old technology:

10110011+1

New Technology:

10010110 11100101 11010110 101010101 11101010 10101110 00011010 10101011 + 00101100

Hopefully this helps to beter understand ECC.

 

[rookie1010]

thanks dude