The consumer electronics giant Samsung has announced its 840 series of 7mm SSDs featuring its new MDX controller with three ARM Coretex-R4 300MHz cores. In another effort to squeeze yet more out the SATA3 interface, the 840 pro claims hefty random IOPS figures of 100,000 read and 90,000 write, with up to 540MB/s read and 520MB/s write, without relying on data compression. Even the basic 840 series has class-leading performance with random IOPS figures of 98,000 read and 70,000 write, however, sequential throughputs are a little lower than the 830 series with up to 520MB/s read and 400MB/s write.
While the use of different NAND grades between the two series is unsurprising, what is a surprise is the use of TLC NAND in the basic 840 series, which is lower grade of NAND typically used in low cost USB flash drives and memory cards. Most SSDs on the market use MLC NAND, which stores 2 bits per cell. TLC NAND stores 3 bits per cell, which while is denser, it is less durable than MLC. The new NAND is also fabricated with 21nm technology, which is also a reduction over 27nm used in its 830 series SSD and as we've noticed before, each stage of miniaturisation results in lower P/E cycle ratings.
Despite all the issues TLC NAND poses, Samsung claims to have improved its NAND fabrication and controller algorithm to the point where its TLC-based 840 are more reliable than many MLC SSDs on the market, not to mention the impressive random IOPS read/write figures this series boasts. For comparison, the 840 series claims read/write IOPS of 98,000/70,000, while the MLC-based 830 with toggle NAND claims 80,000/36,000. We'll have to wait until the first reviews of the basic 840 series to see whether it lives up to its claims and time will tell how durable they really are in the long term.
The 840 Pro will use Toggle 2 MLC NAND (400 Mbps), based on 21nm fabrication. The Pro series other benefits include 256-bit AES full disk encryption, a reliability MTBF of 1.5 million hours and typical power consumption of just 0.054W idle and 0.069W average while active. It will also be backed by a 5-year warranty.
The basic 840 series will feature MSRP prices of $110 for 120GB, $200 for 250GB and $550 for 500GB, with $20 extra for a model with an upgrade kit, including 3.5" mount and cables. The 840 Pro series will be considerable more expensive at $100 for 64GB, $150 for 128GB, $270 for 256GB and $700 for 512GB. They are expected to start shipping mid-October.
