Lexar is demonstrating a prototype 7.5GB/sec NVMe PCIe 4.0 SSD which looks set to be the world’s fastest consumer SSD when it launches next year.
PCIe 4.0 doubles the current PCIe 3.0 bus speed from 1GB/sec per lane to 2GB/sec. Current 4-lane PCIe 3.0 SSDs deliver up to 3.5GB/sec and PCIe 4.0 SSDs such as Gigabyte’s Aorus PCIe 4.0 SSD for gaming systems deliver 5GB/sec. Lexar’s prototype drive goes 50 per cent faster.
The as yet un-named demo drive, as reported by The SSD Review, uses 96-layer 3D NAND organised into TLC (3bits/cell) format and has a 1TB capacity in its M.2 2280 gumstick form factor. Lexar has not revealed controller details except that it is built with a 12nm process and 4 PCIe 4.0 lanes.
LDPC (Low Density Parity Check) error correction code is being used. This can maximise information transfer across a channel suffering noise by filtering out the signal from the noise, i.e. when reading data from NAND cells.
The 7.5GB/sec bandwidth was tested using the IOMeter benchmark. A Crystal DiskMark run delivered sequential reads at 6.2GB/sec and writes at 4.2GB/sec.
Notebooks, desktops and servers using PCIe 4.0 should run significantly faster than today’s PCIe 3.0 systems. Enterprise-class PCIe 4.0 SSDS should go faster still. For example, Liquid’s LQD4500 is an AIC format enterprise SSD using 16 PCIe 4.0 lanes to deliver a massive 24GB/sec.
The Lexar consumer SSD business was spun off by Micron in 2017 and is now owned by Chinese vendor Longsys. Lexar is expected to announce its PCIe 4.0 drive with 512GB, 1TB and 2TB capacity points in Q2 2020. Blocks & Files expects Samsung will have announced its line of PCIe 4.0 class drives by then.
