Link_A_Media Devices LM87800 Controller
One of the most mysterious things about the new SSD series from Corsair is the obscure developer of their controller. However, Link_A_Media Devices (LAMD) isn’t some recent startup of young and ambitious engineers. Founded back in 2004, LAMD has come to the SSD market from the land of magnetic storage where it focused on developing and providing read channel controllers. The company has already shipped over 10 million chips and accumulated a vast experience in signal decoding and error correction algorithms, which is testified to by over 100 patents.
It wasn’t a rush decision on the LAMD part to enter the SSD market, by the way. The company planned to apply its technologies for products with NAND flash quite a long time ago and collaborated closely with Micron for a while, but later made partners with other flash memory makers as well. This work produced its fruit in the middle of the last year in the way of a flexible design for a multifunctional SSD platform. The LAMD solution could be used to create SSDs with SATA, SAS or PCIe interface, choose the number of memory channels at will, and support flash memory chips with different interfaces. In fact, it had everything necessary in both performance and functionality. The platform was especially good in terms of reliability. Drawing on its vast experience, LAMD had adapted some of its clever error correction algorithms to NAND flash.
Although suitable for consumer-class SSDs, that solution went unnoticed for some reason. As a result, Renesas began to manufacture LAMD-based chips for a limited number of enterprise solutions, the Seagate Pulsar.2 being perhaps the most notable of them.
LAMD’s second attempt to become a maker of controllers for mainstream SSDs has been more successful, though. Having the required technology at hand and using their practical experience of dealing with the manufacturers, they had prepared a second platform optimized specifically for consumer-class SSDs by the middle of 2012. It is this platform, implemented in the LAMD LM87800 controller, that is used in the new SSDs from Corsair, the company chosen by LAMD as a strategic partner to promote the new solution.
Of course, the capabilities of the LAMD LM87800 are not as versatile as those of the previous LAMD platform. They have been tailored to what is required of a modern high-performance SSD for desktop and mobile PCs. Specifically, it means the support for the SATA 6 Gbit/s interface and eight channels for flash memory. Each channel can be connected to up to four NAND devices manufactured on 3x or 2x tech process, so the controller can theoretically work with up to 1 terabyte of memory. It is compatible with SLC, MLC and eMLC flash memory with ONFI 2.3 or Toggle Mode 2.0 interface.
Internally, the LAMD LM87800 has something in common with Marvell’s solutions. Like the latter, it contains two ARM microprocessors, one of which is responsible for working with flash memory and another, for the SATA interface. This design results in very competitive specs: a peak speed of sequential operations up to 550 MB/s and a peak speed of random-address operations up to 90,000 IOPS. Theoretically, LM87800-based SSDs are comparable to SSDs based on the best hardware platforms from other developers, Indilinx Everest 2 or Marvell 88SS9187. That’s theory, of course, but we’ll talk about practice shortly.
The LM87800 offers other benefits besides its high specified speed. LAMD has implemented a number of exclusive technologies to make SSDs more reliable. The technologies are referred to as eBoost and include patented real-time error correction algorithms. LAMD claims that its controller meets the reliability standards of enterprise solutions even when working with ordinary MLC memory. The end-user’s benefit is that LM87800-based SSDs come with a longer warranty.