The Vantec UGT-ST450CB is a 2-port eSATA 34mm ExpressCard that supports dual SATA "II" 3.0Gbps transfer via a 1x PCI-E 1.0a interface connection. Thus the combined bandwidth of any attached device(s) is limited to the throughput of the PCI-E bus, at 2.5Gbps or 250MB/s. Even with this potential bottleneck, this is still a vast improvement over the USB 2.0 480Mbps or 60MB/s rate when it comes to utilizing fast external drives. Included in the card packaging are a brief user manual and driver software CD.
The Vantec eSATA ExpressCard uses the narrower 34mm profile rather than the full size 54mm L-shaped cards. This easily accommodates the width of the two stacked eSATA ports, although the body of the card must extend from the slot to allow for the height expansion. Vantec lists the controller as being "fully compliant with SATA 1.0 specifications" which is a little confusing given the claimed SATA 3.0Gbps transfer speed. Although it is not specified by Vantec, as we would later find out the ST450CB uses a Sil3132 controller, which is in fact listed as fully supporting all second generation SATA II features, including 3.0Gbps transfer speeds, Native Command Queueing (NCQ) and hot-swap capability.
Many laptops made since 2005 will include one or two full width 54mm CardBus and/or ExpressCard slots. Since the Vantec ST450CB is a 34mm card, it must be inserted along the left side of the slot, leaving 2cm of gap on the right, as well as another possible 5mm height slot either above or below it. Due to the card not taking up the full width of the slot, and the hot-plug feature of ExpressCard, the Vantec card has several millimeters of side to side play as can be seen by carefully examining the above photos. Although this did not cause any problems during testing, it is something to be aware of, as the cable could pull on the card and work it loose.