Longsys Unveils New SSD Series at the 20th Anniversary

On April 27, 2019, the 20th anniversary celebration of Shenzhen Longsys Electronics Co., Ltd. ("Longsys") was concluded in the newly built Longsys Zhongshan Storage Industrial Park. Taking advantage of the occasion, FORESEE, a brand of Longsys, rolled out S800 and P800 series to make for a more exciting scene.

The two series represent a strong highlight of FORESEE SSD production lines, and it took 2-plus years to develop and produce these products. Here we offer a detailed introduction to S800 and P800 series.

FORESEE S800Series


支持SATA III 6Gbps标准,采用Marvell 28nm DRAM-base主控及原厂3D TLC NAND Flash,提供M.2 2280以及2.5 inch两种物理接口,并有128GB、256GB、512GB、1TB多种容量选择。计划在2019年第三季度全面导入量产。

01 Brief Description

Supporting the SATA III 6Gbps standard, S800 is equipped with a Marvell 28nm DRAM-based host controller and an original 3D TLC NAND Flash, providing both M.2 2280 and 2.5-inch physical interfaces, and diverse densities of 128GB, 256GB, 512GB, and 1TB. The series will be put into mass production in the third quarter of 2019.


02 Technical Features

a. FORESEE-developed product firmware

The self-developed firmware can ensure more stable product performance. And a credit-based scheme for delay optimization is adopted to ensure the stable performance of SSD read/write.

b. Marvell LDPC-based error correction technology

The self-developed optimized software decoding capacity can improve error correction as much as possible.

In a nutshell, LDPC error correction consists of hardware decoding and software decoding. Similar to BCH error correction, hardware decoding has only the hard-decision data as input and can be realized with one read. More like the essence of LDPC error correction, software decoding enables repeated read and fine-tuning of the parameters of multiple reads according to conditions, to acquire the "soft data" of different groups. Then multiple iterative operations take place by combining the soft data with log-likelihood ratio (LLR) to finally complete LDPC software decoding.

c. Using non-1:1000 SDRM mechanism

After the optimization of FORESEE's self-developed firmware, the product can switch freely between the storage mapping table of SDRAM and NAND ARRAY, realizing more efficient application of SDRAM and NAND ARRAY, to meet the needs of frequent random write and scenarios with many concurrent data.

FORESEE P800Series

01 Brief Description

Supporting the PCIe Gen3x4 standard, P800 is equipped with a Marvell 28nm DRAM-based host controller and an original 3D TLC NAND Flash, providing a M.2 2280 interface and diverse densities of 256GB, 512GB, 1TB, and 2TB. With random read speeds up to 3,200MB/s, it can meet the demands of PC OEMs for high-performance SSD products. The series will be put into mass production in the third quarter of 2019.


02 Technical Features

The product firmware is developed by FORESEE and can be customized to meet different requirements of clients.

The firmware of P800 has the following features:

a. Free Block Acceleration (FBA)

The self-developed firmware of P800 has two SLC Cache zones, namely fixed SLC Cache zone and adjustable SLC Cache zone. By adjusting SLC Cache zones, products will have more high-speed ranges.

b. Initialization Data Acceleration (IDA)

IDA uses SLC mode, which can reduce the time it takes to install operating systems, and enhance the safety and reliability of data.

c. Marvell LDPC-based Error Correction Technology

Efficient computing and forecasting of re-read table will further optimize the self-developed firmware, and can reduce the time of error correction to improve user experience.

d. Data Rollback Mechanism

The firmware is designed with an enhanced power-loss protection mechanism. When SPOR happens, the firmware will judge the validity of current data and the security of previous data, to ensure the reliability of write-in data.

Besides the above-mentioned two products, FORESEE will offer more competitive SSD products in the future to meet customers' demands, and to make further progress in the development of TB-level storage products in a new era.