Introduction:
JMB321 is a single chip. It integrated six independent SATA channels and a micro-processor. With proper setting, the chip can be configured as an 1 to 5-ports Serial ATA II Port Multiplier or a 5 to 1-port Serial ATA II Port Selector. JMB321 contains 15 GPIOs which can be configured as various standard interfaces. It also has the capability to load external firmware code to extend its functionality
Features:.
Compliant with Serial ATA II Port Multiplier Spec. Revision 1.2 
Compliant with Serial ATA II Port Selector Spec. Revision 1.0
Compliant with Serial ATA High Speed Serialized AT Attachment Spec. Revision 2.5
Supports 6-port 3.0 Gbps SATA II interface
Supports SATA II Gen2i and Gen2m(External SATA Connection, eSATA) 
Automatically speed negotiation for 3 Gbps or 1.5 Gbps
Supports Native Command Queue (NCQ) 
Supports Hot-Plug
Supports PM aware and non-PM aware host
Supports Asynchronous Notification
Supports ATAPI drives 
Supports partial / slumber power saving mode
GPIO 
1.Supports 15 GPIOs
2.Supports I2C interface
3.Supports ISA interface
4.Supports SPI interface 
5.Supports firmware extension
System Requirements:
Windows 8/7 (32 / 64 bit) / Vista / 2008 64 bit / 2003 (32 / 64 bit) / 
XP / 2000
Package Contents
1 x SATA II Port Multiplier 5-Port Card
3 x SATA Cable
1 x Power Cord
1 x User Manual　　　
Note:Purchase products, please make sure your computer has PM features