Comay EECC technology

What is ECC technology? What is Enhanced ECC(EECC) technology?

ECC stands for “Error Correcting Code”. It is one kind of error correction and encryption-decryption algorithm. ECC technology can greatly improve the reliability of SSD. It the the prerequisite for Nand Flash to be used normally.

Meanwhile, the endurance is determined by ECC capability.

There are bad blocks when the Nand was produced. Afterwards, more bad blockswould occour. For the sake of reliability, bad block managment technology monitors and manages the bad blocks. However, mostly, there are only one or several bits of errors occur instead of whole page or block. ECC is supposed to fix such errors.



Generally, the strength of ECC is measured by max capability to fix errors. For instance, the ECC strength is 16 bit per 512B user data.

The EECC, is one kind of Enhanced ECC. The strength is doubled from general 16 bit/512B.


Why SSD need EEC?


1. EECC can greatly improve reliability

With the development of process of Nand Flash, the error rate is become higher.

It is indicated that UBER would decrease to only one tenth if the ECC capability doubled.

2. EECC can greatly extend endurance

The endurance is determined by ECC capability and EECC can greatly improve the endurance, finally the endurance of SSD.

As one of the most advanced technology, there is not a solid conclusion about the effect of EECC. Generally, it is believed that the endurance will increase 2-5 times.

With help EECC-like technologies, Anobit, LAMD claimed that they have greatly extend endurance.

Anobit annouced that they can prolong the lifespan of nand flash from 3,000 to 50,000.


FAQ about EECC


Value of EECC?

As above, EECC can greatly improve endurance, reliability of SSD at the price of trival cost increase.

Generally, UBER will become only one tenth and lifespan of SSD will increase by ten times if ECC capability doubled. EECC is the right key.


Can EECC eliminate the limit of Nand Flash endurance?

The effect of EECC is very amazing. However, there is no evidence that the limit can beeliminated.