Key Factors To Consider When Creating A Media Storage System

We've been seeing an increase in questions about storage lately, and our editorial focus has had an emphasis on storage this year. With that in mind, we have been collecting questions, and that has led to more questions that some of you might not have even contemplated yet.

We sincerely hope this story gives you some more insight about what your best options for creating a media storage system that stores your data efficiently, effectively and safely.

The data throughput requirements for a number of major formats are listed in Figure 1. Many formats have very minimal throughput needs, so just about any disk subsystem can handle all of the major consumer video formats with no issues.

There are many factors that go into determining the speed of a particular hard drive. The biggest considerations are spindle speed and areal density. A drive with higher areal density means that more data will be moving under the drive's heads per revolution.

Interestingly, this means that larger-capacity drives often have higher data transfer rates than smaller-capacity drives. But it also means that you have to watch your numbers carefully - it's rare, but not unheard of, for drives with high spindle speeds to have lower performance than some drives with not-as-fast spindle speeds but large capacities.

Don't believe us? OK, let's go over to one of our favorite benchmark utilities, SiSoftware Sandra. According to their collected benchmarks of physical disks, the fastest benched physical drive as of the time of our test is the Western Digital WD740HLFS, which is a 74GB 10K RPM drive. It operates at 105.28MB/sec. However, Western Digital also made the WD1600AAJS, 7200 RPM 160GB drive that is almost as fast at 96.621MB/sec. On the other hand, there's also the WD740GD, also a 74GB 10K RPM drive, which can attain only 61.956MB/sec. So spindle speed is not necessarily an indicator of a high data transfer rate - there's more to it than that.

The fastest drive of all the drives tested in this particular version of Sandra is a 64GB SATA SSD, which benches at 160.001MB/sec. (We'll talk more about SSDs in a moment.)

To get more performance out of multiple drives, you can put those drives into a RAID... we'll talk more about those a little later as well.

The operational principle of a hard drive is a set of platters spinning at a high speed, with tiny heads hovering very close to (but not touching) the surface of each platter. (A common analogy is that of a modern jumbo jet aircraft flying at full speed but only a few inches from the ground.) So, to pull that off, a hard drive needs to have platters with an extremely smooth surface and, ideally, no bumps from the outside world to cause problems. This is why your computer's hard drive should never be opened; even the tiniest smoke particle that landed on your hard drive's platter could be disastrous. This is also why hard drives include small filters to clean the air coming into the drive. Ideally, your computer should also never be moved when it's on (this also means that you should really close your laptop's lid before picking it up).

The solution that you are looking for might be a RAID, which stands for Redundant Array of Independent Disks. This describes a technology that allows multiple drives to be addressed together to show up in on the computer as a single volume. The "redundant" part of the name is a bit of a misnomer, though, since there are some configurations where there is actually no redundancy. See Figure 2 for a quick outline of RAID levels.

It is extremely important to note that using a RAID is not a substitute for keeping proper backups. You still need to make backups of your most important files.

Yes. While many motherboards out there include RAID functionality, it is often not of the same caliber or flexibility as that available from third parties. Not only can a third-party controller allow you to use different types of drives (e.g., if you wanted to use SCSI, SAS or Fiber Channel drives, you could probably find a controller that would let you do that), they generally include their own processors to free up your computer's processor. This is especially important if you are running a RAID 5 or RAID 6.

That said, if you want to put together a simple stripe or mirror set of SATA drives, the performance of the RAID controller on the motherboard is generally pretty decent. It's a good way to dabble in the advantages of RAIDs, to help you decide whether you want to go ahead and spring for the fast controller and enterprise-class hard drives.

We're not really sure, and that is something a lot of people are very curious about. Over long stretches of time, it is possible that the lubricant for the drive motor may leak out onto the platters, which would destroy both the motors and the platters. If you've got a really critical project, using redundant formats, e.g., writing the same project files to several different formats (or even extra copies onto the same type of media) would be very wise. You might consider writing to a USB Flash drive or Blu-ray Disc (or both!) in addition to a hard drive.

Yes, very much so. Like any other type of media, it's recommended to keep anything that stores data in a range of comfortable temperatures. Shoot for 68°F at 40% relative humidity, but, in general, if you're comfortable, your drives (and other media) should be fine.

Yes. The way Flash memory is written does not involve magnetic fields, so theoretically nothing should cause the premature erasure of any data on an SSD. Long-term, however, we are curious to see the effects of time on the data stored on SSDs and other Flash media.