Continuing with our study of currently available multi-channel (four and more) Serial ATA RAID controllers, we came across the FastTRAK S150 SX4 card from Promise Technology. The name of this controller suggests its cognation to the FastTRAK S150 TX4 (see our Promise FastTRAK S150 TX4 Controller Review). Well, they do have something in common – they both support four SerialATA-150 devices and this fact explains the similar-sounding model names. As for the difference, the FastTRAK S150 SX4 seems to be a more advanced version because of the RAID5 support it provides, but we will also see some deeper differences on a closer inspection.

So, again, this controller supports up to four SerialATA-150 devices (and arrays of up to 1 terabyte capacity). The types of arrays supported are standard, including 0, 1, 10, 5 and JBOD. The controller’s ability to work in a 32-bit/66MHz PCI 2.2 slot provides a maximum theoretical bandwidth of 266MB/s. The FastTRAK S150 SX4 allows using up to 256MB of cache memory (64MB being the necessary minimum). Moreover, the controller’s PCB carries chips of Ferroelectric RAM for keeping a transactions log and integrated General-Purpose I/O ports for controlling the device. 

FastTRAK S150 SX4 also allows expanding the array’s capacity and changing its level while online. It supports two caching modes (write-back and write-through) and anticipatory reading based on application and data types. Then, it uses batch commands and merges interrupts to minimize their number and optimize their execution.  It also supports load balancing (for mirrored RAID arrays only) and elevator seek (for streamlining commands based on the data location on the disk).

Closer Look

The controller is not small, but nevertheless all electronic components are very compactly arranged on its entire PCB surface. A PDC 20621, a XOR processor, resides in the center. To the left, there is a 168-pin DIMM slot – the memory module is situated in parallel to the controller PCB. Four SerialATA connectors are located along the upper edge of the card.

Judging from the outward appearance, the FastTRAK S150 SX4 has much more in common with the FastTRAK SX4000 card than with the FastTRAK S150 TX4. Well, it is true: the FastTRAK S150 SX4 is actually a FastTRAK SX4000, which has been trained to talk to SATA drives via Marvell converters.

The basic parameters of the controller are listed below: