Is there ever such a thing as too much storage? In my opinion, not really. While I rarely keep enough "live" data, meaning, information I access frequently, to fill up 200GB, I tend to be something of a pack rat. I'll download tons of files, and forget about them. Eventually, one day I'll do an audit and see well over 350GB just sitting there.

The Windows MCE PC I'm currently running is loaded with a terabyte of storage, and is frequently used to record television content. Surprisingly enough (maybe not for all of you), after about 2 months, we're now down to the last 150GB of free space. Who would have guessed all those 2 hour season finales I've yet to watch would add up so quickly.

The days of 80GB to 120GB drives for enthusiasts are pretty much over. Games can easily eat up 3GB at a time, demos several hundred megabytes and don't forget all the P2P goodies that we know all of you collect (don't worry, your secret is safe with us).

Today we'll be looking at Seagate's monstrous Barracuda 7200.10. While the 750GB is the item that will grab everyone's attention, all the usual features we've come to expect are present, such as NCQ, and SATAII/300. Seagate does introduces Perpendicular Recording Technology which is a a new technology for their desktop drives.

The Seagate Barracuda 7200.10

The Barracuda 7200.10 is a standard sized 3.5" hard drive, so it should fit just fine in any internal drive bay that follows specifications. Below is a quick cheat sheet comparing the 7200.10 to the 7200.9 and the 7200.8 which we've looked at in the past:

	7200.10	7200.9	7200.8
Speed (RPM)	7200	7200	7200
Cache (MB)	16	16	8
Platter Size (GB)	188	125	133
# of Platters	4	4	3

On the surface, there doesn't appear to be much difference between the Barracuda 7200.10 and 7200.9 (other than the obvious capacity differences), but with Perpendicular Recording Technology now making it to the Barracuda, they couldn't be any more different.

Perpendicular Recording

The easiest way to create bigger hard drives is to increase the areal density. Seagate's desktop 400GB drives for example use 133GB platters, and therefore require fewer platters than they would if the areal densities were lower. While this is an effective way of expanding storage, it can become very costly, and much harder to maintain reliable data stores.

Conventional drives (such as previous Barracudas and many desktop drives from other manufacturers) rely on longitudinal recording. What this means is that the bits are laid horizontally along the plane or surface of the disk. In theory, 250 Gigabits/square inch should be possible with longitudinal recording technology, but to do this, the data bits must continue to shrink and packed closer together. Eventually, as we hit the 250 Gigabits/square inch limit, the bits become to small and demagnetize.

Current longitudinal recording have a specific magnetic orientation as shown in the left image in the picture above. When these bits get smaller as explained earlier, they begin losing the ability to hold their magnetic orientations. As a result, the bit's magnetic north and south poles reverse without warning and corrupt data.

Perpendicular recording addresses the shortcomings of longitudinal recording by aligning the bit magnetization in a "standing" position. The soft underlayer illustrated above acts as part of the write field return path that produces an image of the recording head that effectively doubles the recording field.

Kudos to anyone who actually understood all of that, but here's an example forwarded to us from Seagate themselves:

"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 (the coercively for techies) 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."

Seagate has already introduced this technology for their notebook drives (the Momentus 5400.3 to be specific) and their Cheetah 15000.5 Enterprise drives. As larger capacity drives are introduced, it's likely almost all of them will be based on this technology. As seen in the cheat sheet above, the Perpendicular Recording allows for much denser platters than before, weighing in at 188GB.

Perpendicular Recording is only one of a few key technologies Seagate is now introducing with their Barracudas. Clean Sweep is designed to automatically calibrate your drive each time you power up. For those of you who move your PCs around a lot, this will be very helpful in keeping your drives more reliable. Due to the differences in every computer's operating environment, Adaptive Fly Height can adjust the distance between the disc head and platter and maintain consistent read/write performance from the beginning to end of the disk's workload.

The Barracuda 7200.10 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 7200.9 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. Provide 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 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 7200.10 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.

Our review sample uses an Agere chipset for its SATA controller, but we are aware that some units may have a ST Micro Serial ATA controller chipset. We're guessing that this was a recent change and all new drives will use the ST Micro chip. Just above the Agere chipset is the 16MB of cache memory.