Comay rSLC Technology

What is rSLC technology?


Generally speaking, technologies such as Wear Leveling, Over-provisioning, Bad block management are developped techniques. These techniques are employed by almost all SSDs.

We are not going to discuss on such topics. We only want to show some unique methods CoreRise developped and applied.

rSLC technology is one of the unique technologies CoreRise uses to extend the endurance of SSDs.

 

rSLC technology can extend the endurance of normal MLC Nand Media to 2~5 times than it supposed to be with only a little bit cost increase.

This technology can deliver wonderful solutions with enough endurance at a lower price for some certain budget-tight applictions and clients.

 

In-drive-UPS

Morever, rSLC technology can greatly improve the performance and reliability at the same time!

 

Whay endurance-extending technology is important for SSDs?


1. Endurance of Nand Flash is limited

The endurance of Nand Flash is limited.

At prezent, endurance of SLC is 100K times, MLC ranges from 1000 to 3000 times. For TLC, it in only 500.

2. Write amplification cut the endurance of Nand Flash

Write amplification fator ranges from 4~100 typically. As a result, the endurance of SSDs can be 0.25~0.01 times as supposed to be. A SSD with normal MLC can be wirte for only 30 times or more!

 

In a word, the endurance of SSDs are limited.

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Generally, what kind of technologies are used to extend endurance of SSD?


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1. Wear Leveling

2. High/low page

There are two logic page in each page of a physical page of MLC Nand Flash. Generally, these two logic pages are called high page and low page.

High page is very different from lower page.

The performance of high page is much better than lower page, as well as endurance.

If only high page is used, MLC Nand flash behaves just like SLC Nand for both of performance and endurance.

This feature is use by some SSD makers to extend endurance of SSDs.

There are two drawbacks for this technology.

One is the WA fator will increase dramatically.

The other drawback is only half of the capacity can be used of MLC Nand Flash. In other words, the cost doubled.

3. WAR(Write Amplification Reduction) Technology

WA factor is from 4~100 typycally.

If aggressive garbage collection policy employed, the sustained performance would be wonderful. However, WA factors goes higher.

Some SSD makers try their bests to reduce WA factor to entend the endurance.

4. rSLC technology

rSLC technology is one kind of technolgy related to EECC, signal processing, etc.

By rSLC technolgy, the endurance of SSDs can be greatly improved with no cost increase.

There are similar technologies employed by other companies such as Anobit, LAMD,etc.

Anobit claimed that the endurance of SSDs is extended to 17 times as longer as supposed tobe.

LAMD also anounced dramatic increase of endurance.

Aside from endurance, another advantage of rSLC technolgy is cost. All Nand Flash capacity can be utilized.

 

FAQ about rSLC


 

Q1: What effect can rSLC reach for endurance of SSDs?

At present, there is no clear answer for this question.

It is beleived that rSLC can extend the endurance of MLC Nand flash to 5-20 times longer than it is supposed to be.

 

Q2: Would rSLC technology run at the price of performace decline or cost increase?

No.