Presentation 2009-10-20
Prolongation of Lifetime and the Evaluation Method of Dependable SSD
Kensuke TAI, Masato KITAKAMI,
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Abstract(in English) Storage capacity of solid-state drive (SSD) which has a large number of flash memories is rapidly increasing in recent years. Because high-density flash memories tend to have errors within their data easily, the reliability of SSD decreases even if using conventional error control method. Also, flash memory cells have a limited number of erasure cycles. Therefore, if many writes concentrate into the same part, the memory cells are broken and become unable to store the data. Wear-leveling is used for leveling the erasure cycles in a flash memory. The cells are broken and lifetime of memories is shortened because it is hard to catch the characteristics of the actual data. This paper proposes wear-leveling and error control method by using some flash memories in SSD in order to improve SSD reliability and lifetime. In the proposed method, error control is usually executed, and wear-leveling among the channels is executed when there is a bias in the erasure cycles. In addition, the execution frequency of wear-leveling is adjusted in consideration of deterioration of the cell. Evaluation of bit error rate and lifetime shows that the proposed method has high reliability and durability.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) solid-state drive (SSD) / flash memory / wear-leveling / error control code / lifetime prolongation
Paper # DC2009-23
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Committee DC
Conference Date 2009/10/13(1days)
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Paper Information
Registration To Dependable Computing (DC)
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) Prolongation of Lifetime and the Evaluation Method of Dependable SSD
Sub Title (in English)
Keyword(1) solid-state drive (SSD)
Keyword(2) flash memory
Keyword(3) wear-leveling
Keyword(4) error control code
Keyword(5) lifetime prolongation
1st Author's Name Kensuke TAI
1st Author's Affiliation Graduate School of Advanced Integration Science, Chiba University()
2nd Author's Name Masato KITAKAMI
2nd Author's Affiliation Graduate School of Advanced Integration Science, Chiba University
Date 2009-10-20
Paper # DC2009-23
Volume (vol) vol.109
Number (no) 238
Page pp.pp.-
#Pages 6
Date of Issue