RAM | Reseller Advocate Magazine: Issue 72

By Chris Angelini

On the desktop, your customers add it if they’re running a small form factor platform without the room to upgrade. Most drive vendors also sell external drives bundled with backup software, since the combination of mobile, high-capacity hardware and an app like EMC’s Retrospect Express makes good sense.

Even as you start working with customers buying workstations and servers, network-attached storage (NAS) devices continue to be popular. You’ll still find entry-level business boxes with external drives attached for backup. But more common are storage servers expanded out through JBOD enclosures.

Until recently, there were two popular interfaces connecting external disk drives to host machines, at least on the desktop. USB 2.0 is still the most prevalent, thanks to widespread adoption and integration by your favorite chipset vendors. The other, known as FireWire or its official IEEE 1394 designation, is more of a staple in Mac platforms and consumer electronics devices. Both interfaces center on high-speed serial buses pushing, at the very least, 400 Mb/s of data. That’s up to 50 MB/s—-perfect for quick backups and more than sufficient for streaming stored media. USB and FireWire support hot-plugging as well.

Because USB and FireWire are so similar in terms of performance, most external drives work with both of them. Higher-end units commonly add FireWire 800 support, bumping the throughput cap to 100 MB/s. FireWire 800 is less common, though, because the controller chips cost more. Generally, the only way for a reseller to enable the faster interface is through an add-in expansion card.

The Rise Of A Third Interface

Neither USB nor FireWire will fall out of favor any time soon. Both interfaces support a wide range of peripherals, from keyboards and mice to high-definition cameras. But as far as storage is concerned, eSATA is the brand-new option your customers might not yet know about.

The eSATA specification has actually been a standard for a long time. But you know how these things go. Transitioning from a specification on paper to product availability to mainstream adoption takes time and-—more specific to the channel—-education. Fortunately, there’s not a whole lot to learn about eSATA’s nuts and bolts because most of the spec’s defining qualities mirror what you already know about internal SATA. The specification does dictate a maximum cable length of 2 meters. It also increases minimum transmit potential and decreases minimum receive potential to better cope with the electrical variations found “outside the box.” Of course, cables and connectors are enhanced. Otherwise the protocol and signaling are the same, so hardware vendors can put standard SATA drives in eSATA enclosures without compatibility worries.

Your customers are going to want eSATA for more than just its similar interface though. By design, the eSATA drives selling today transfer data at up to 3 Gb/s. Compare that to the 480 Mbps ceiling of USB 2.0 and the 800 Mb/s cap on pricey FireWire 800 equipment. At 3 Gb/s, you’re talking about a maximum of 375 Mb/s, though. Is the extra bandwidth of any use at all? To a point, yes. The FireWire 400 interface tops out at 50 Mb/s. Single SATA hard drives can move in excess of 100 Mb/s. Just as you’d find in an internal storage subsystem, individual SATA drives are not able to saturate a single SATA link. But going outside the box opens doors to new and exciting technologies that can make better use of eSATA’s surplus throughput.

What do you need in order to get started with eSATA? As with USB 2.0, the basic infrastructure is being laid by motherboard vendors integrating eSATA on their boards. Intel’s DP35DP, for example, employs a P35 Express chipset with the latest ICH9R I/O controller. The core logic supports up to six SATA ports and the board enables all of them, including one port meant to accommodate eSATA drives. Other vendors, such as ASUS, put eSATA ports right on their boards’ back panels. The P5K Premium/WiFi-AP comes with two ports in the back, ready for your customer’s foray into eSATA.

The Emergence Of eSATA Drives

One of the first eSATA technology demonstrations took place in February 2005 at Intel’s Developer Forum. Power users have kept an eye out for shipping product ever since, knowing eSATA would blow right past the performance of USB or FireWire. And now that the chipsets and motherboards are shipping with built-in eSATA ports, three years later, drives are on store shelves.

When a customer comes asking about a backup solution or external media repository, eSATA is the way to go. Seagate and Western Digital sell two of the most elegantly bundled eSATA products. The Seagate FreeAgent Pro ships in capacities as high as 750GB and supports USB 2.0 and FireWire 400 in addition to eSATA (just in case the drive is transported to a system lacking the newer interface). From the perspective of hardware, Seagate’s drive is quite simply a SATA 3 Gb/s disk inside a flexible enclosure that can take full advantage of the eSATA spec. Software is what sets it apart, though, automatically copying specified content to multiple locations for easy access and setting restore points to protect against data loss.

Western Digital’s My Book Premium ES Edition is more focused on backup. The 500GB drive is housed in a sleek, black box accentuated with an onboard capacity gauge and eSATA/USB 2.0 support. Power management circuitry automatically turns the drive on and off in concert with its host computer. And Western Digital’s bundle includes EMC’s Retrospect Express software, which is one of the most feature-complete backup apps you can offer to SOHO customers.

Unfortunately, neither the Seagate FreeAgent nor the Western Digital My Book come with the eSATA cables you’d need to use the interface. VARs selling those two drives either need to carry cables or go with another product that does a better job emphasizing eSATA connectivity, such as Iomega’s 500GB eSATA Professional Hard Drive.

A media aficionado doesn’t need the value-added software or fancy flashing lights of the Seagate and Western Digital drives. He’s simply looking for more storage space and an interface fast enough to stream high-def content. The Iomega drive is a great choice for that customer. Although it comes with the same backup software package as Western Digital’s My Book Premium ES, a diminutive form factor lets the Iomega drive blend in while the other two command attention. Of course, it also helps that this 500GB eSATA disk costs less than its competition.

Need More Storage

While most motherboards sport as many as 12 USB 2.0 ports, you’d be hard pressed to find a board with more than two eSATA connectors. But wait-—we’ve already established that a single 3 Gb/s link can move more information than any single attached hard drive. What if there was a way to connect multiple drives to each port and take advantage of that throughput?

Now you’re getting into eSATA’s real value. One way to offer greater eSATA connectivity would be through a hub, which works like a USB or Ethernet hub. In essence, one SATA port connects to a port multiplier, which enables a number of other points, all sharing that first port’s bandwidth. In the case of eSATA, it’d take at least three or four hard drives running at full tilt in order to saturate the upper bounds of a single link. DATOptic’s SATA2_HUB takes a single eSATA input and, using Silicon Image’s 3726 3 Gb/s port multiplier, connects up to five eSATA drives. Almost ironically, the drive is powered by a USB connection because SATA links don’t carry power.

The other way to go would be an external enclosure with port multiplier functionality already built in. Enhance Technology, Inc. sells an attractive four-drive enclosure called the EnhanceBOX E4 that can condense the capacity of four drives into a single eSATA connection. The E4 series actually consists of three separate models. The first has four point-to-point eSATA connections, the second leverages an InfiniBand cable, and the third uses a port multiplier to turn one eSATA cable coming from your customer’s chassis into four SATA 3 Gb/s connections.

Take the port multiplier route to maximize performance, maintain the simplicity of a one-wire connection, and keep cost as low as possible. The EnhanceBOX E4-PM sports its own 80W power supply, four hot-swappable hard drive trays, and a handful of chassis management features that will let you know if a drive or fan goes out. Load the enclosure up with drives and connect it to a video-editing workstation. Your customer will enjoy the performance of an internal disk array from a compact desktop box.

Making Connections

eSATA might be making its grand debut on a handful of higher-end enthusiast motherboards, but the interface is far from prolific yet, despite its compelling advantages. So now that you’ve seen some of the solutions out there and have a better idea what the interface can do, it’d be a shame to not offer it the next time a customer comes looking for external storage. But how do you connect an eSATA drive to a system lacking support for eSATA? Break out the expansion cards, of course.

On the desktop (or in a workstation), eSATA is easily attainable through a drop-in PCI Express upgrade, such as SIIG’s eSATA II PCIe Pro RAID card. The $129 board centers on Silicon Image’s Sil3132 chipset. The chipset supports two eSATA ports signaling speeds up to 3 Gb/s (careful, some cards are limited to 1.5 Gb/s rates) and RAID 0 and 1 for basic performance or data protection functionality. Installation is a snap: The card literally installs into any available PCI Express slot. It helps, of course, that SIIG includes drivers for Windows 2000, XP, Server 2003, and Vista.

The great thing about external disk drives is that they’re mobile. You can take one, run a backup, and move the drive offsite to protect against a natural disaster. Or you can load a drive with MP3s at home and hook it up to a notebook on the road. Vendors selling eSATA drives understandably want to support as many interfaces as possible, but in order to give your customer the best experience possible, enable eSATA across all of his devices. No eSATA on the laptop? Not a problem; SIIG sells those too.

Drop an eSATA II 2-port ExpressCard into notebooks with an open ExpressCard/34 slot. The slim peripheral isn’t much larger than a pack of gum, yet the stacked eSATA ports still manage to each support 3 Gb/s signaling over the equivalent of a PCI Express x1 connection. Or step things up a notch with the eSATA II ExpressCard RAID that fits into the larger ExpressCard/54 slot. Based on the same Silicon Image chipset as its desktop RAID board, the larger SIIG card similarly takes a pair of eSATA drives in a RAID 0 or RAID 1 configuration.

eSATA Or Bust

Do a quick Google search on eSATA and you’ll quickly find a handful of other ideas for turning your customers on to the technology. Expand the storage on a Series3 TiVo using eSATA, enable eSATA using extender cables that turn internal SATA ports into back panel eSATA connections, and create your own eSATA solution by dropping the SATA drive of your choice into an external enclosure, potentially trumping the capacity of other eSATA solutions. There’s a lot of potential here, despite the fact that eSATA is really a one trick pony designed solely for storage.

Resellers looking to add more value to their whiteboxes should keep an eye out for motherboards with eSATA already integrated. Also pay close attention to the drives you’re selling. Many vendors are still weighing heavily on USB 2.0, leaving eSATA cables out altogether. Your customers won’t pay anything extra for eSATA. In fact, Western Digital’s 500GB eSATA drive costs less than its 500 GB FireWire drive. Faster hardware for less money? Sure, we’ll take it.