JMicron and DSS, here are two words that the association brings back bad memories. Indeed, the JMicron controller JMF602 has been widely used by many SSD manufacturers simply because he was one of the few on the market and in addition it was cheap. The rest is familiar with consumers frustrated and disappointed at the finish. If the SSD-based JMF602 behaved rather well in sequential reads and writes and provided good flow with the handling of large files, the random write operations and treatment of small files were simply disastrous! The result screen freezes in Windows or incredibly slow in some operations. The culprits were first unable to send a memory cache external to the controller but also more memory on-die insufficient 32K only. When you know that flash memory cells are typically organized in blocks of 128 KB, it is not without its problems. Widely adopted in the beginning, this controller has been gradually abandoned in favor of the Comptroller of the Samsung but especially Indilinx Barefoot controller which is currently the best days of many brands. It must indeed admit that he is convincing even if he suffers from performance degradation over time, failure remedied by the TRIM under certain conditions.
JMicron reacts with a new controller called JMF612. This has much to do to give some credit to the mark on the SSD market and some companies like OCZ does not know yet if they will sound experience with the Taiwanese firm. This JMF612 corrects errors JMF602 and is finally able to make a memory chip to act as external cache. The size of this chip DDR or DDR2 can vary from 128 Mbps to 2 Gbps, or 16 to 256 MB The controller itself is equipped with 128 KB of cache and 32 KB of programmable ROM. This JMF612 supports NAND Flash chips etched in 5x, 4x and 3x nanometers. JMicron evokes support MLC chips Samsung, Toshiba, Hynix, Micron and IM Flash. No word yet on the possible support of SLC chips. This controller is compatible with the standard S-ATA 3 Gbps but also with USB 2.0, Jmicron continuing to include the possibility of connecting the SSD with USB 2.0. The Taiwanese firm announces sequential speeds of 250 Mb / s read and 200MB / s write, depending on the course of Nand Flash chips used. Let us not wait any longer to test the controller, in world first it seems.