If it isn't already obvious, storage space is getting to be more and more important. High definition content is using much more space than previous forms of media, and the smallish quarter terabyte drives we've been using a mere 2 years ago really won't cut it these days. In a recent review, we've pointed out that a 10 second OTA HD signal consumes about 25MB. That's 9GB gone for just one hour of recording. Despite not watching much "live" TV, I do like to record a lot of television to catch up on later and it's clear that if I want to record in HD, I'll need a lot of space.

Enough of that banter, since if you're here reading this article now, you're already aware of all of this. One terabyte drives are in full force now, and today we'll be looking at the Seagate Barracuda 7200.11. While this series of Barracudas come in a variety of capacities, we're focusing on their 1TB model.

The Seagate Barracuda 7200.11

Like all of their consumer drives, the Barracuda 7200.11 is a standard sized 3.5" hard drive, so it should fit just fine in any internal drive bay that follows the usual IDE specifications. Below is a quick cheat sheet comparing the 7200.11 to the 7200.10 which we've looked at in the past:

	7200.11	7200.10
Speed (RPM)	7200	7200
Cache (MB)	16 or 32	16
Platter Size (GB)	250	188

The biggest change from the 7200.10 to the 7200.11 is the increase in platter size. We mentioned there will be a few capacities offered, but we can sum it up by saying that there will be 3; 500GB, 750GB and 1TB. If you're shopping for the 1TB version, another change from the previous model is the doubling of cache from 16MB to 32MB. The 500GB and 750GB will only ship with 16MB. As the name implies, the Barracuda spins its drives at 7200rpm, allowing for a sustained transfer rate of 105MB per second. Keep in mind that this is a number provided by Seagate, and we have no numbers officially regarding their earlier products.

Going back to the platter size increase we mentioned last paragraph, the easiest way to create bigger hard drives is to increase the areal density. Seagate was able to cram a lot of space into their previous 7200.10 through the use of Perpendicular Recording Technology. Perpendicular recording addresses the shortcomings of longitudinal recording by aligning the bit magnetization in a "standing" position. Seagate has already introduced this technology earlier with the Barracuda 7200.10, their Momentus 5400.3 and their Cheetah 15000.5 Enterprise drives. The Barracuda 7200.11 introduces the second generation of Perpendicular Recording where we now jump to 250GB platters.

To explain Perpendicular Recording, you can think of it this way. Magnetic recording is a lot like sewing. Think of the magnetic field from a write head as a needle, and the recording layer of a disc as the cloth you are trying to sew. The fabric is the magnetic strength of the disc and the needle is the strength of the write head (the write field) Your data is the seam in the fabric. The more stitches per inch, the more data you store. To make your data durable, you want to use a thick fabric, and a long needle, but this gets in the way of making many stitches to the inch.

In longitudinal recording, the magnetic layer (the cloth) is laid directly onto the aluminum substrate. When data is written, it is like sewing with the cloth laid flat on a table. Going flat along the table, the needle can only make stitches far apart. If you use a shorter needle, and thinner cloth, the stitches get closer together, but the seam gets weaker and weaker. When the material gets too thin, the seam tears, and the data is lost.

In perpendicular recording, a soft underlayer is put down between the substrate and the recording layer. The soft underlayer lifts the cloth off the table, letting the needle go into the cloth straight up and down. Now you can put stitches very close together, and still use a long needle, and thick cloth. Your data seam has more stitches, and it is stronger as well.

As the larger platters increase areal density, it allows Seagate to build large capacity drives with fewer platters. Few platters mean less power consumed (about 1W at idle and load according to Seagate's specs comparing the 7200.11 to the 7200.10) as well as increased performance given that the data is more tightly packed. With Seagate's SoftSonic motor and fewer platters (when compared against competitor's equivalent capacity drives), the Barracuda should be quieter as well.

The Barracuda 7200.11 is a native SATA product and supports speeds of SATA 3.0Gb/s. Unlike some of the first batches of SATA drives, a native drive will bypass the legacy Task File reads and writes, as well as avoiding the limitation of 133 Mbytes/sec for Ultra DMA Mode 6 transfers. While the 7200.11 supports SATA 3Gb/s transfer speeds, it is backwards compatible with SATA 1.5GB/s hosts. SATAII mode is also supported by the drive and it is enabled by default. Provided your motherboard supports it, it would be a good idea to leave it this way, but be sure to flip the jumper position if not. One of our forum readers in the past had an issue with a MSI P4N Diamond (no SATAII support) and a Seagate drive and changing the jumper corrected his problem of the drive not being detected.

As with all Barracudas starting with the 7200.7 series, the Barracuda 7200.11 fully supports Native Command Queuing (NCQ). Introduced with the Serial ATA II spec, this is a feature that can only be found in native SATA hard drives. Unlike LCQ, NCQ works by allowing a drive to process multiple commands at the same time. These commands can be rescheduled or reordered on a whim, and can also issue new requests while the drive is retrieving data from the previous request. While NCQ support is present on the drive, the controller used will also need to support NCQ in order to take advantage of it. As with the previous NCQ enabled Barracudas, the drive will work fine without an NCQ controller.