A quick guide to the ins and outs of choosing a hard drive
Back in the 20th century drive choice was a little simpler: hard or floppy. These days when it comes to a hard drive, things aren’t so easy to figure out. You have choices between spinning platter and SSD, 5400 rpm and 7200 rpm, burst and sustain transfer rates, not to mention JBODs and RAIDs with their levels 0,1,1E,2,3,4,5,5E,6,00,10,1E0 and 50.
Don’t panic. By the end of this article it’ll all make sense, and you will understand how to choose a Video Production Hard Drive (except for the bit about RAIDs–we’ll cover that in an upcoming article).
Solid state (SSD) versus spinning platter
Currently there are two main technologies in use for fast storage: spinning platter drives and solid state drives (SSD’s).
Spinning platter drives are the old school. They have a set of physical platters or disks inside that spin rapidly, storing your data magnetically on the platters. There have been constant advancements since their introduction sixty years ago, but the basic 3.5” drive hasn’t changed much since 1983. Same rectangular box, just more bits of data squeezed inside every year.
SSD’s are a whole different beast. They use digital flash memory, similar to the RAM in a computer, but without losing data when the power turns off. SSD’s are faster, more reliable, lower in power consumption, less prone to physical impact damage and more likely to keep your data around when you stick them on a shelf.
Why would you choose a spinning disk drive over an SSD? There’s really only one reason, but it’s a good one: price. At least right now spinning disks are much cheaper per MB than SSD’s. That’s changing of course. Every year they’re getting cheaper and SSD’s are expected to eclipse spinning platter drive sales by 2020.
By the way, don’t be fooled by smaller form-factor drives. They may
be SSD’s, but they could also be 2.5 inch spinning platter drives, common in laptops and other smaller devices.
5400 rpm versus 7200 rpm
This only applies to a hard drive, but there are typically two speeds for physical spinning platter drives: 5400 rpm (revolutions per minute) and 7200 rpm. If you’re like me, you assume faster always means better. With hard drives that’s only partly true.
7200 rpm drives are definitely faster at transferring data. Faster = more bits per second, which means you’re going to have an easier time playing back higher definition and less compressed video streams. BUT–and here’s the thing that most of us don’t stop to think about–that speed also means more heat and greater power consumption.
These days companies like LaCie are engineering 5400 rpm drives to provide the consistent speed throughput you need for video work, so you’re not necessarily gaining anything by going with a 7200 rpm drive.
For a dedicated workstation, 7200 rpm drives are great. But for portable situations–like the set of your latest project–you’ll be safer with a 5400 rpm drive. It’ll give you longer battery life, less heat and potentially less chance of failing on you.
Transfer rates – burst versus sustained
Drives are rated for both burst and sustained throughput. Burst throughput is great for general computing, where you’re trying to grab a bunch of different office docs and your OS is pottering about with temp and cache files. But for video work it’s all about sustained transfer.
We want to make sure that our video steadily streams off the disk. So when you’re deciding whether a drive is fast enough, focus on the sustained data rate, not the burst.