Performance Trade-Offs in Using NVRAM Write Buffer for Flash Memory-Based Storage Devices

2009 ◽  
Vol 58 (6) ◽  
pp. 744-758 ◽  
Author(s):  
Sooyong Kang ◽  
Sungmin Park ◽  
Hoyoung Jung ◽  
Hyoki Shim ◽  
Jaehyuk Cha
Keyword(s):  
Flash Memory ◽  
Storage Devices ◽  
Trade Offs ◽  
Write Buffer

scholarly journals Compression-Assisted Adaptive ECC and RAID Scattering for NAND Flash Storage Devices

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2952 ◽  
Author(s):  
Seung-Ho Lim ◽  
Ki-Woong Park
Keyword(s):  
Flash Memory ◽  
Error Recovery ◽  
Recovery Phase ◽  
Error Correction Codes ◽  
Nand Flash ◽  
Nand Flash Memory ◽  
Flash Storage ◽  
Storage Devices ◽  
Complementary Method ◽  
Compressed Data

NAND flash memory-based storage devices are vulnerable to errors induced by NAND flash memory cells. Error-correction codes (ECCs) are integrated into the flash memory controller to correct errors in flash memory. However, since ECCs show inherent limits in checking the excessive increase in errors, a complementary method should be considered for the reliability of flash storage devices. In this paper, we propose a scheme based on lossless data compression that enhances the error recovery ability of flash storage devices, which applies to improve recovery capability both of inside and outside the page. Within a page, ECC encoding is realized on compressed data by the adaptive ECC module, which results in a reduced code rate. From the perspective of outside the page, the compressed data are not placed at the beginning of the page, but rather is placed at a specific location within the page, which makes it possible to skip certain pages during the recovery phase. As a result, the proposed scheme improves the uncorrectable bit error rate (UBER) of the legacy system.

scholarly journals Evaluating Encryption Algorithms for Sensitive Data Using Different Storage Devices

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Bahman A. Sassani (Sarrafpour) ◽  
Mohammed Alkorbi ◽  
Noreen Jamil ◽  
M. Asif Naeem ◽  
Farhaan Mirza
Keyword(s):  
Flash Memory ◽  
Full Range ◽  
Data Encryption ◽  
Storage Device ◽  
Sensitive Data ◽  
Hard Drives ◽  
Storage Devices ◽  
Aes Algorithm ◽  
Encryption Algorithms ◽  
Storage Encryption

Sensitive data need to be protected from being stolen and read by unauthorized persons regardless of whether the data are stored in hard drives, flash memory, laptops, desktops, and other storage devices. In an enterprise environment where sensitive data is stored on storage devices, such as financial or military data, encryption is used in the storage device to ensure data confidentiality. Nowadays, the SSD-based NAND storage devices are favored over HDD and SSHD to store data because they offer increased performance and reduced access latency to the client. In this paper, the performance of different symmetric encryption algorithms is evaluated on HDD, SSHD, and SSD-based NAND MLC flash memory using two different storage encryption software. Based on the experiments we carried out, Advanced Encryption Standard (AES) algorithm on HDD outperforms Serpent and Twofish algorithms in terms of random read speed and write speed (both sequentially and randomly), whereas Twofish algorithm is slightly faster than AES in sequential reading on SSHD and SSD-based NAND MLC flash memory. By conducting full range of evaluative tests across HDD, SSHD, and SSD, our experimental results can give better idea for the storage consumers to determine which kind of storage device and encryption algorithm is suitable for their purposes. This will give them an opportunity to continuously achieve the best performance of the storage device and secure their sensitive data.

Singulation of Electronic Packages With Abrasive Waterjets

2005 ◽  
Author(s):  
Mohamed Hashish
Keyword(s):  
Flash Memory ◽  
Cutting Speed ◽  
High Volume ◽  
Cutting Process ◽  
Electronic Packages ◽  
Digital Cameras ◽  
Storage Devices ◽  
High Cutting Speed ◽  
Machine Reliability ◽  
Abrasive Waterjets

Abrasive waterjets were used for the first time to commercially singulate electronic chips such as those used for flash memory cards found in digital cameras, cell phones, and USB storage devices. Cutting these components requires high cutting speed, high edge quality, accuracy, and precision. For example, a minimal accuracy needed is about 0.1-mm and a minimum Cpk of 1.33. A relatively small AWJ (~ 0.38 mm) was successfully used to accurately cut chips at speeds of 20 mm/s to 60 mm/s. It was determined that the use of machine vision is critical to meeting the accuracy requirements. The cutting process consisted of piercing starting holes and then cutting shaped pattern cuts to contour the chip components. Drilling holes was performed without delamination and the cutting speed was optimized to meet the intricate chip geometry. Because of the relatively high volume of components to be cut, requiring around the clock duty, process and machine reliability are of critical importance. This paper discusses the results and observation of the cutting process as well as the performance of the system.

scholarly journals Experimental trade-offs between different strategies for multihop communications evaluated over real deployments of wireless sensor network for environmental monitoring

2018 ◽  
Vol 14 (5) ◽  
pp. 155014771877446 ◽  
Author(s):  
Santiago Felici-Castell ◽  
Juan J Pérez-Solano ◽  
Jaume Segura-Garcia ◽  
Miguel García-Pineda ◽  
Antonio Soriano-Asensi
Keyword(s):  
Environmental Monitoring ◽  
Flash Memory ◽  
Wireless Sensor ◽  
Multihop Routing ◽  
Trade Offs ◽  
Basic Features ◽  
Multihop Communications ◽  
Efficiency And Reliability ◽  
Monitoring Application ◽  
Better Than

Although much work has been done since wireless sensor networks appeared, there is not a great deal of information available on real deployments that incorporate basic features associated with these networks, in particular multihop routing and long lifetimes features. In this article, an environmental monitoring application (Internet of Things oriented) is described, where temperature and relative humidity samples are taken by each mote at a rate of 2 samples/min and sent to a sink using multihop routing. Our goal is to analyse the different strategies to gather the information from the different motes in this context. The trade-offs between ‘sending always’ and ‘buffering locally’ approaches were analysed and validated experimentally, taking into account power consumption, lifetime, efficiency and reliability. When buffering locally, different options were considered such as saving in either local RAM or FLASH memory, as well different alternatives to reduce overhead with different packet sizes. The conclusion is that in terms of energy and durability, the best option is to reduce the overhead. Nevertheless, sending larger packets is not worthy when the probability of retransmission is high. If real-time monitoring is required, then sending always is better than buffering locally.

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