The Need For Speed and Space: What Do You Need To Store Video?
To record, edit, or do just about anything with digital video, you need adequate storage space to store your video files. However, stating this obvious truth doesn't really help anyone, does it? You may be asking yourself, "How much storage do I need on my drives?" Or, "Is any old hard drive good enough for playing back my video files?" For the TL;DR folks out there, the answers are "a reasonable amount" and "not necessarily," respectively. If that's not enough information, read on! I'm going to discuss computer-connected video storage in general, some drive-speed guidelines, and how you can check to make sure that your storage devices can support the media you're dealing with.
How Much Storage Do I Need on My Drives?
The partially sarcastic response that I could give to this question would be "Well, how much storage do you need?" I only say that with partial sarcasm because the amount of storage one may need depends on what kind of video that individual intends to store, and what they intend to do with it. Logic dictates that higher-resolution video demands more space. Generally speaking, 4K video needs more space than HD video, and HD video requires more space than SD video. Luckily, the storage density of individual drives seems to have kept up with the times, so you don't need a mountain of drives to store a single 4K project.
As far as strict capacity is concerned, buying the largest drive you can afford is usually the best way to go if you're going to be shooting, capturing, or editing a lot of video. Hard drive manufacturers with a focus on the creative market, like G-Technology and LaCie, offer external single hard drive options up to 12 terabytes and 10 terabytes in size, respectively. If you're more interested in an internal solution, newer helium-filled SATA drives can store up to 12 terabytes! If you need even more storage, or just want more security over a possible drive failure, buying multiple drives and using them in a RAID array is a great option. External RAID solutions are also available in varying sizes and interfaces. Various capacities and drive selections can be considered, depending on your workload.
Capacity is one thing, though, and for most video-related applications, there is another important, and perhaps more important, aspect to storage, and that is speed. On to question #2!
Is Any Old Hard Drive Good Enough for Playing Back My Video Files?
Drive speed is likely the most important factor in selecting a drive for video work. I remember, from my time taking video production courses in college, my professors would wax poetic about 7200 RPM drives as being the only ones fast enough for editing purposes. They would also sing praises to the FireWire interface of yore, heaven-forbid you should use the dreaded USB! This was at a time where DV reigned supreme, HD was the fancy new thing, and 4K was but a pipe dream for everyone who wasn't shooting with RED cameras or the Dalsa Origin. While a hard drive from that era could probably handle a relatively light workload today, times have changed though, and storage technology has advanced by leaps and bounds. Most modern interfaces today, including USB 3.1 and Intel Thunderbolt 2 and 3, are fast enough to deal with mainstream video codecs and bit-rates.
While the Thunderbolt and USB interfaces are sufficient for high-resolution video, the drive itself, where your videos are stored, can be a severely limiting factor. The maximum data rates for Thunderbolt 3 and USB 3.1 Gen 2 are 40 Gb/s and 10 Gb/s, respectively. Those rates are rarely (if ever) attainable, even with the fastest SSDs on the market, which is why you can't just trust the advertising speak that usually accompanies hard drives achieving 5 Gb/s speeds over USB 3.0.
Learning About Your Drive's Speed
So, how do you find out how fast your drives really are? You can employ a few useful pieces of software to benchmark your storage. One of the most ubiquitous video-focused programs comes from Blackmagic Design. The company's Disk Speed Test software was originally designed to complement its SSD recorders to test-drive compatibility. This simple software writes a temporary file to a target drive and analyzes the transfer speed and the read-back speed. After doing this, Disk Speed Test displays the true data rate and the maximum frame rates of popular codecs that can be sustained with those read/write speeds. Another great option is from AJA. Its System Test software has more advanced features than the Blackmagic option, providing visual feedback with graphs showing transfer and read speeds, as well as a PCI-Express testing utility and video format capabilities. Both solutions work well for internal and external drives or drive arrays.
I like Blackmagic Design's software because it shows multiple formats and frame rates at a glance, with easy-to-read "speedometers," indicating true drive speed. Here are a few tests I did with a variety of drives that I use.
The above result of paltry 51.4 MB/s write and 64.1 MB/s read speeds was achieved using an older consumer-grade 5400 RPM drive connected via FireWire 800. With its low read and write speeds, I would not really recommend this drive or similar drives for any sort of professional capture or editing. This kind of drive would advertise "FireWire 800 speeds for 800 Mb/s transfer," and not really coming close. The fact that this drive achieves even half of that is somewhat surprising to me.
Stepping up to a 7200 RPM drive connected via USB 3.0, you can see the immediate benefit of higher transfer speed brought about by the higher rotational speed and the additional bandwidth of the drive connection. This drive can carry out most basic HD single-camera ProRes editing workflows. Again, this is an older drive, and not one that I would really recommend for anything other than basic workloads.
The drive I personally use as my edit drive is a Lexar Pro Workflow 512GB flash drive. I've edited HD multi-cam projects and basic 4K projects from this drive. Multi-cam 4K productions would probably require faster storage, such as HDDs or SSDs in a RAID configuration, though this type of drive is sufficient for my current workflow. Though it's faster than my hard drives, it doesn't have enough capacity to really store more than one project at a time, so I use larger, slower storage to archive projects.
While benchmarking is handy for drives that you already have, you can't benchmark a new drive while it's inside the box before you buy it. Hard drives intended for the creative market, like the G-Technology and LaCie options mentioned above will usually have relatively accurate figures for their read and write speed, as opposed to posting the maximum speed of the interface, a misleading practice that occurs with more consumer-directed products. Since the major advantages of SSDs over hard drives is speed, SSD manufacturers usually advertise accurate, though optimistic, statistics for drive speed, regardless if the SSD is consumer or enterprise grade. Interestingly, as hard drives' capacity goes up, so does their speed. My 2TB drive at home (the 7200 RPM drive benchmarked above) can get up to around 100 MB/s and newer high-capacity drives can achieve speeds well over 200 MB/s, approaching the speed of SSDs.
The bottom line is, if you test your drive speed and you know what kind of video you're going to be dealing with, you will know when it's time to upgrade to faster storage. As a general rule, SSDs are faster, and can be great tools for editing high-resolution video or playing back multiple video streams for multi-camera projects.
There are quite a few variables that go into hard drive selection for professional workflows. Buying hard drives that are designed for creative work and feature accurate read and write speed information is a good place to start, and as you start taking on more advanced work, buying RAID units and SSD storage could definitely help your workflow. Capacity and speed are usually tradeoffs with one another unless major investment is made in larger arrays that have a combination of speed and high capacity.
What storage solutions do you recommend for professional video workflows? Is there anything that I missed? Is it even worthwhile to benchmark your drives? Leave a comment below and get the discussion started.