Page 2 : The 1TB WD Blue SSD, Interface, SSD Controller, Flash Memory, SDRAM Cache
The 1TB WD Blue SSD
The 1TB WD Blue SSD (WDS100T1B0A) looks like any other 2.5″ slim hard disk drive. It was, after all, built to conform to the 2.5″ form factor, allowing it to easily replace any 2.5″ hard disk drive with a height of 7 mm. But there’s no doubt about its solid state nature when you pick it up – it’s very light!
The label on the underside has a lot of important information, like the model and serial numbers in case you need to RMA it. The label also lists interesting details like the date and place of manufacture. This particular drive was manufactured in China on 9 September 2016.
As it only serves to protect the NAND chips, SSD controller and circuit board inside from static damage, the case is made from plastic. In fact, it will sound hollow when you tap on it because the SSD internally does not take up much space.
SATA 6 Gb/s Interface
Like all Serial ATA drives, it comes with the standard SATA data (left) and power (right) connectors, and is hot-pluggable. That means you can connect and disconnect this solid state drive while the PC is still running. There is no jumper block, because there’s really nothing for you to set. It’s just plug and play!
The Marvell 88SS1074 SSD Controller
The 1TB WD Blue SSD uses the Marvell 88SS1074 SSD controller, which boasts the following key features :
- Supports up to 4 NAND channels, with up to 8 NAND chips per channel
- Features Marvell’s third-generation NANDEdge low-density parity check (LDPC) technology
- Supports SATA 3.2 (6.0 Gbps)
- Toggle 2 and ONFI2 support at up to 400 MT/s
- Integrated DEVSLP (Device Sleep) mode for low power support
- Supports 256-bit AES hardware encryption
- Built on 28 nm CMOS process
The Marvell NANDEdge LDPC technology allows for reliable on-the-fly error correction of the 3-bit TLC flash memory, with minimal impact on latency, performance and power consumption.
However, the Marvell 88SS1074 is likely to fall short in sustained throughput, because it only supports 4 NAND channels. Competing controllers like the Phison S10, for example, boast 8 NAND channels, allowing twice as many NAND chips to be accessed simultaneously.
The SanDisk TLC Flash Memory
To keep costs low, the 1TB WD Blue SSD uses TLC (Triple Level Cell) flash memory chips, where each cell holds 3-bits. These are SanDisk second-generation planar TLC chips, built on the 15 nm process. There are a total of eight of these TLC flash memory chips, each with a capacity of 128 GB.
The Micron DDR3L SDRAM Cache
The 1TB WD Blue SSD has a large 1 GB write combine cache, courtesy of two Micron MT41K512M8RG-107 chips. These are DDR3L SDRAM chips with an effective clock rate of 1866 MHz (DDR), a voltage of 1.35 V, and a storage capacity of 512 MB.
This large SDRAM cache allows the WD Blue SSD to mitigate the TLC flash memory’s inherently poor write performance. It also allows writes to the SSD to be combined, reducing wear on the flash memory cells and extending their lifespan.
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