Its chips are used by a number of companies, such as ASUS, Gigabyte, and MSI in PC motherboards, though because of difficulties, newer MSI models have moved to using integrated Marvell controllers.
SSD Controllers 
JMicron's JMF601 and JMF602 SATA flash controllers were reported to have issues with write latency, causing a stuttering problem. The performance problem was attributed to the small buffer size used in the controller. Some manufacturers tried to get around the problem by using 2 JMicron controllers and added more cache, but this increased the cost and still failed to deliver the improved performance. In June 2008, JMicron released version B of the affected controllers, which claimed to improve write latency and allow reserving more spare blocks to overcome the issue, but Anandtech's test showed that although JMF602B has twice the cache of the JMF602A controller and has less stutter, 4KB random write has 74x the latency and under 2% write speed of Western Digital VelociRaptor 300GB.
JMicron's SSD controller is widely adopted by many SSD manufacturers such ASUS Eee PC, Corsair, OCZ, and Transcend. JMicron was the first company to provide an SSD controller chip to these companies, allowing them to produce reasonably priced MLC SSDs. JMicron was to announce a new SSD controller with a DRAM cache in Q3 2009, but no such announcement occurred.
JMF602 would be succeeded by JMF612.
Linux Compatibility 
JMicron SATA/IDE controllers are often incompatible with some boot loaders. In particular, those using GRUB, such as Ubuntu, cannot boot in some conditions (2006/08, 2.6.17). The 2.6.18 Linux kernel and JMicron controller BIOS 1.06.53 solved these incompatibilities, but may not be present in existing products, or may require re-flashing the motherboard BIOS. Other bootloaders such as the Windows NTLDR boot loader and EXTLINUX work fine. It has been fixed by the latest distros.
Security breach 
According to the comprehensive analysis of Stuxnet virus released by Symantec in 2011, a JMicron digital certificate for Windows got compromised, allowing attacker to digitally sign malicious drivers, then revoked by Verisign : "The attackers would have needed to obtain the digital certificates from someone who may have physically entered the premises of the two companies [Realtek and JMicron] and stole them, as the two companies are in close physical proximity." states the report.
JMicron makes products for a number of different applications, including:
- PATA-SATA translation Bridge
- USB-ATA bridge
- 1394+USB-SATA bridge
- PCI-Express-ATA bridge
- PCI Express-1394 bridge
- SATA Port Multiplier/Selector with RAID
- PCI Express-Ethernet bridge
- USB+SATA flash controller
- SSD controller
- PCI-Express flash card readers
- JMicron's product list
- Reference to JMicron on ASUS website.
- MSI's original P965 Neo-F with JMicron controller
- MSI P965 Neo-F version 2, with JMicron controller replaced
- OCZ Once Again Slashes the Price of Core Series SSDs
- G.Skill, Intel & Patriot SSD group test
- Avoid SSDs with Jmicron's JMF602 Controller
- Super Talent Claims Its SSDs Can Rock Intel's
- Ng, Jansen (22 January 2009). "Exclusive Interview With JMicron on SSD Controllers". DailyTech. Retrieved 2009-01-23.
- The SSD Anthology: Understanding SSDs and New Drives from OCZ
- SSD Prices Could be Cut in Half Due to New JMicron Flash Controller & 32nm NAND Flash
- Bug #57502: JMicron PATA/SATA Controller does not work
- JMicron FAQ
- W32.Stuxnet Dossier - Version 1.4 (February 2011)