Intro To SSDs
Layered SSD/HDD hybrid storage system has been widely used. However, most traditional designs are performance oriented, and not optimized for SSD lifespan. In this paper, SSD lifespan oriented layered model and cache algorithm are proposed. To decrease SSD wear rate, HDD-RAM switch tunnel is appended to the traditional layered hybrid structure. Cache window size is considered in cache algorithm to filter data, avoiding unnecessary cache cost. Results show optimized designs significantly reduced erase times on SSD, and slightly influenced original performance.
SSDs Compared to HDD
As semiconductor technology develops, computer storage design has been enormously changed. Solid state drive (SSD) is gradually displacing traditional magnetic rotation drive (HDD). Compared with HDD, SSD has higher performance and better reli-ability, while it consumes lower power and creates fewer fragments. SSD greatly improves nonvol-atile I/O, which eliminates bottleneck between RAM and HDD.Although SSD has such advantages, its cost is very high.
The Cost Of SSD Storage
The cost of traditional HDD is only 0.06$/GB, while the cost of SSD is generally 0.5$/GB. Considering limited budget, it is unrealistic for traditional storage systems to replace all HDDs with SSDs. In order to balance cost and perfor-mance, a hybrid storage system needs to be deployed, which contains both high-capacity HDD and high-performance SSD.
Hybrid SSD Storage
In most hybrid storage system, highly accessed data are cached in SSDs, and cold data are stored on HDDs. There are two typical deployments: One is layered storage structure, which deploys SSD as upper cache and HDD as lower switch storage; the other is parallel storage structure, which deploys SSD and HDD in the same layer. If you’re not interested in hybrid storage, and instead just want best speeds, check out these 1tb nvme ssd. The layered storage structure is easier to realize, generally just appending SSD to original systems. While parallel storage design needs to modify original structures and access controls, which reduces system reliability and portability.
The Fastest Storage
Presently, the fastest consumer storage technology available is NVME which replaces AHCI and utilizes the PCIe slots (in different form factors).