Closer Look at Promise SuperTrak EX8650
Released in early 2008, the 600 series of Promise’s controllers marked a new level for the company that had not offered SAS-supporting controllers before. The series includes controllers to suit everyone’s taste: all-hardware (with an integrated processor) models with four, eight or 16 internal ports, two models with external ports (one has eight external ports and another, four internal and four external ports), and two simple models with software implementation of RAID0 and RAID1 arrays. You can easily distinguish them by the model name: the first numeral denotes the number of the controller’s ports, the second numeral is the series number, the third numeral reports the interface (every model of the series has 5 in this place, meaning PCI Express) and the fourth numeral stands for the number of external ports. The models with an integrated processor belong to the SuperTrak EX subseries while the software controllers belong to the FastTrak TX subseries.
The SuperTrak EX8650 controller we’ve got for our tests is not the senior model, yet it can satisfy most users with its eight ports and an 800MHz Intel XScale 81348 processor. By the way, you can note how the processor frequency has grown up. We used to see frequencies like 300-500MHz before, but now even the basic 4-port model of this series is equipped with a 667MHz processor while the 16-port model and the models with external ports have a 1200MHz processor. The increased performance of HDDs calls for higher performance of the XOR-processor so that the array would not be limited by the latter. And thanks to the ongoing progress, top-performance processors have become now considerably cheaper. They get hot at work, so the processor chip is covered with a massive heatsink on the controller.
It’s all right about memory. The controller has 256 megabytes of DDR2 SDRAM with error correction on board. The models with external ports have twice this amount, i.e. 512 megabytes, like the 16-port controller. Anyway, this amount of memory should be enough, especially if used effectively.
The rest of the device’s parameters are typical enough: a low-profile PCB, a PCI Express interface, two SFF-8087 connectors for drives (you can attach up to four drives to one such connector using special interface cables). Like becomes a serious controller, this one supports a battery backup unit, but the BBU is not included into the kit by default.
Of course, the controller supports all the popular array types that you can build out of eight drives, namely: RAID 0, 1, 1E, 5, 6, 10, 50, and 60. The three last types are two-level combinations of two types of arrays. It is a kind of an array built out of arrays: RAID1, RAID5 or RAID6 arrays (the first numeral of the two-level array indicates the type) are striped.
It’s all right about OS support, too. The manufacturer’s website offers drivers and useful software for Windows, FreeBSD and Linux for download.