The two most popular questions I get every day in my email concern media management and system configuration. In this article I want to tackle system configuration.
These thoughts apply to all video and audio editing systems on both Mac and PCs.
EXECUTIVE SUMMARY
If there’s one really important piece of advice I can share its this: Don’t obsess over configuring the “best system.” Look for a system that meets your needs and budget.
Technology changes daily. Whatever you buy today will be out of date next week and no longer sold next year. The absolute best system today won’t be worth anything in four years; and six years from now we’ll wonder how we could get any productive work done with it.
We need to change the question from: “What’s the best?” to “What do I need to meet my needs?”
SYSTEM CATEGORIES
We need to pick our hardware depending upon three broad categories of editing:
Clearly, it would be great to configure a system that handles everything all the time in real-time with no problems. However, most of us don’t have that kind of money lying around.
Again, we need to change the discussion from “I want it to do everything,” to “I need a system that handles my current editing with room to grow in the future.” This means that we need to take a hard look at the kind of editing we are doing and what we plan to do for the future.
SIDE NOTE: STANDARD DEFINITION VIDEO (SD)
If all you or your clients need to edit is SD video, any computer and virtually any hard disk will be fine. (For most editing, USB 2 is too slow to be reliable. However, it will be fast enough to edit simple DV video on Windows. I recommend FireWire 800 for DV editing on the Mac.)
All DVDs always-and-only display standard def video. As long as you have a DVD burner, you don’t need a really fast computer. Yes, video compression will benefit from faster computers. However, if all you are doing is compressing for DVDs, you won’t see speed gains significant to justify the cost of buying a high-speed computer solely for DVD video compression.
IMAGE SIZE, FRAME RATE, AND VIDEO CODEC
Any currently shipping computer can edit HD video with few problems. Most medium- to high-end computers can edit 2K or 4K images, again, with few problems. The computer is no longer the key device it used to be. The issue with larger frame sizes is not the speed of your computer, but the speed and capacity of your storage.
For most single-stream, HD video editing, a single hard drive attached via Thunderbolt, USB 3, or FireWire 800 will be sufficient. (I do not recommend editing HD video using USB 2 or FireWire 400 devices.)
Here are a few typical codecs and data rates:
Keep in mind that data rates double for unrendered footage when dissolving or wiping between two video clips for the duration of the transition.
A single spinning media hard drive transfers data around 120 MB/second (85 MB/second for FireWire 800). This speed is more than adequate for standard HD editing.
SIDE NOTE: CAN I USE SSD DRIVES
SSD drives are blindingly fast. Speeds 4 – 5 times faster than standard spinning media are typical from a variety of vendors. However, there are two big downsides to SSD drives. They:
If money is no object, SSD drives make a huge difference in performance. However, if you need the maximum amount of storage without breaking the bank, the best use of SSD drives is to use them as your boot drive. This provides screaming performance for the operating system, applications and all background processes. Then, use standard hard drives and RAIDs for media storage on external devices.
NOTE: I do not recommend storing media on your boot drive. It is too small if you are using an internal SSD drive and too slow if you are using a standard hard disk. All media should be stored on a hard drive other than the boot drive. In most cases, this means an external device.
AS FRAME SIZES GROW
As frame sizes grow, you need to graduate from a single hard drive to a RAID. This is a collection of hard drives that act as a single, very big, very fast hard drive. (Here’s an article that explains RAIDs in more detail.)
“But wait a minute!” (I hear you say.) “I have a Thunderbolt hard drive, isn’t that fast enough?”
No.
Whether you connect a singe spinning hard drive via Thunderbolt 1, Thunderbolt 2, USB 3.1, USB 3, or, to a more restricted extent, FireWire 800, the speed of the hard drive is NOT based on the protocol (how it’s connected), but the speed of the drive itself.
Within a few percent, the fastest a single hard drive can go, without flash (SSD) acceleration, is around 120 MB/second. (FireWire 800 maxes out around 85 MB/second.) This means that the only way storage gets faster is to gang drives together; which is what a RAID is all about.
As a rule of thumb, as frame size doubles (720p to 2K, from 2K to 4K) data rates quadruple (um, go up four times!). This means that as you start editing high-resolution images, you will very quickly exceed the speed of a single hard drive. VERY quickly!
HOW BIG A RAID?
The rule of thumb that I use to approximate RAID data transfer rates is to multiple the number of drives in a RAID by 100 to determine its data transfer rate.
This means that a 4-drive RAID will deliver data to or from your computer around 400 MB/second. (Yes, this varies by RAID configuration (RAID 0 vs. RAID 5), whether it uses flash to accelerate transfers, and other technical factors. However, as a rough guide, this is pretty good.)
This also means that if you take a 4-drive RAID and connect it via Thunderbolt 2, it won’t transfer data at even Thunderbolt 1 speeds. In other words, the protocol is way faster than the drives you are using.
UM, HOW ABOUT SSDs AGAIN?
Yup. Using an all-SSD system will make things really fast, but, again, you are trading off total storage. For me, I’d rather add more spinning disks to gain speed, than switch to SSD (which is really fast) and spend a lot more money to get the storage I need.
NOTE: If you need speed more than storage space, an all-SSD RAID is blazing fast. Not cheap, but really, really fast.
I’M EDITING AUDIO, WHAT ABOUT A JBOD INSTEAD OF A RAID?
A JBOD (“Just A Bunch of Drives”) looks like a RAID, but each drive can be accessed independently. Recently, in another article I wrote about RAIDs, a sound engineer reported that they recommended using JBODs for audio editing and effects, rather than a RAID, because the performance was better.
So I checked with a couple of RAID vendors that also make JBOD devices, as well as some professional sound effects engineers.
They all agreed that, in general, RAIDs deliver faster performance than a JBOD for most audio editing. This is a subject I will explore further in additional articles.
WHERE DOES BIT-DEPTH FIT IN?
Bit-depth determines how accurately our digital images represent reality. The higher the bit-depth, the more accurately the color (and gray-scale) values reproduce what our eyes can see. However, there’s a trade-off: The higher the bit depth, the bigger the file.
For example:
| Bit-Depth | Color / Gray-scale Values | File Growth |
|---|---|---|
| 8 | 256 | 1x |
| 10 | 1,024 | 4x |
| 12 | 4,096 | 16x |
| 14 | 16,384 | 65x |
| 16 | 65,536 | 256x |
Whew! Without compression, these files can become gigantic! This is another reason for the adage: “You’ll spend far more for storage than you’ll ever spend for your computer.”
CHANGING CODECS
The one place where faster computers will make a difference is in dealing with some of the newer codecs.
H.264 is notorious for being difficult to decompress in real-time. G-5 computers, for example, could not even play H.264 files reliably. Canon has some codecs in their DSLR cameras that require really fast gear.
If you are working with older cameras, you can also use older computers. However, don’t assume that all modern codecs will play reliably on older gear. Sometimes the processor just isn’t fast enough.
This is a good place to point out that testing a video format for compatibility and performance on your editing gear before shooting that major motion picture can save a ton of heart-ache in the editing suite after the fact.
NOTE: Keep in mind that for short-term projects that are outside the capability of your normal setup, computer gear and editing systems can be easily rented and shipped anywhere. That is often a more cost-effective choice than buying all new gear.
SINGLE VS. MULTI-CAMERA EDITING
Just as storage becomes the gating factor as image size or bit-depth increase, so also storage speed (data transfer rate) becomes the gating factor as you start to edit multicam sequences. Again, even an iMac can easily edit a 12-stream multicam sequence; it isn’t the computer, its the speed of your storage.
Each stream in a multicam stream is a full video stream. For example, when editing ProRes 422 at 1080p 50 or 60:
Even a two stream edit is going to tax a single hard drive because the heads can’t switch between the two streams fast enough for reliable playback.
As you start to do more multicam editing, you’ll need a high-speed RAID connected via Thunderbolt.
HEY, HOW ABOUT AN SSD RAID?
Yes, for multicam work, an SSD RAID will be a big improvement over spinning media. You won’t be able to store as much on it, but your multicam editing will fly.
Another good technique is to convert your multicam source files to proxy files for the purposes of multicam editing, then switch back to full-res when the multicam is done.
WHAT HAPPENS IF I DO LOTS OF EFFECTS
When it comes to effects, the rules change. Storage is no longer important, graphics process is. Both Final Cut and Premiere are off-loading more and more processing to the GPU (Graphics Processing Unit). This means that if effects are your bread-and-butter, for example editing commercials or motion graphics, you don’t need massive storage, you need massive GPUs.
The trend in today’s video editing software is to push as much of the image processing to the GPU as possible. The more effects work you do, the more you will benefit from a high-speed GPU. From what I’ve been told by both Adobe and Apple, the difference between OpenCL and CUDA has, essentially, disappeared. Both will do an excellent job in graphics processing.
NOTE: Before buying a GPU, however, make sure it is compatible with your software – not all GPU cards are.
WHERE DO I SPEND MY MONEY?
Here is my recommendation on where to spend money. Not all systems can be customized, so look at the specs of each unit and pick the one that comes closest to what you need:
For the budget-limited:
For straight editing
For multicam editing
For effects-heavy editing
IF I CAN’T GET THUNDERBOLT, HOW ABOUT USB 3.1?
First, your computer needs to support USB 3 or 3.1. Plugging a USB 3 device into a USB 2 port only slows the USB 3 device down to USB 2 speeds.
USB 3.1, the latest version of USB, is the fastest version of USB yet, but it isn’t as fast as Thunderbolt. Also, the USB protocol is designed for moving small packets of data, while Thunderbolt is designed for moving massive media files.
If you are on a PC and don’t have access to Thunderbolt, then mini-SAS, USB 3, USB 3.1, or FibreChannel are all excellent options with serious speed. eSATA isn’t necessarily as fast, but it will also be a good, economical choice when editing fewer streams of multicam video. Given the choice, eSATA is a better choice than any version of FireWire.
WHEN SHOULD I CONSIDER THUNDERBOLT 2?
The only way the data transfer rate of your storage is going to fill a Thunderbolt 2 pipe is using a RAID with 20 spinning hard disks, or ten SSD drives. Anything less won’t do it.
Thunderbolt 2 is designed, for now, to drive 4K video monitors, not storage bandwidth. Storage vendors are supporting Thunderbolt 2 not because they need to – they don’t – but because they don’t want to be at a marketing disadvantage when they are shipping Thunderbolt 1 and the competition is shipping Thunderbolt 2.
For virtually all editing today – except stereoscopic 3D, high-bit depth, multicam editing – an 8-drive RAID will be more than enough. And, in fact, for most of us, a 4-drive RAID will be sufficient.
NOTE: Another reason storage vendors are supporting Thunderbolt 2, is that when you connect a Thunderbolt 1 device as part of a chain of Thunderbolt 2 devices, the entire chain slows down to Thunderbolt 1 speeds. While probably not affecting your storage at all, this would have a serious impact on any external video monitors you are using.
SUMMARY
As you’ve discovered, the computer isn’t the focus of configuring a system. The challenges are storage, GPUs and understanding the kind of editing you are doing.
There is no one perfect editing system, because each of us is doing different kinds of editing. My goal in this article is to help you ask the right questions as you plan your next system.
Don’t get caught in the “What’s the Best?” trap. Think about your needs and find the gear that meets them on a budget you can afford.
As always, I’m interested in your comments.
One Response to Configure Your System
Larry,
Thanks for article “Configure your system”. I often tell folks that the place to start is “what throughput do you need” i.e. type of video, codecs, muti-cam and number of effects, etc… determine what you need in terms of computer system. Nice to have an article I can send people too that compares the bit rates required.
Been planning on making a grid chart based on bit rates needed vs. storage throughput so people can make smart choices.
A couple of things I think should be considered.
I know of no USB3.1 devices including computers that are currently shipping. Love to know if any are? USB3.1 and the new type C connector, Display Port and Alternative Mode shows great promise. Looking forward to it next year. Anandtech has a good article on it here…http://www.anandtech.com/show/8558/displayport-alternate-mode-for-usb-typec-announced
As to USB3.0, I think it is important to talk about UAS(UASP; USB Attached SCSI Protocol) vs BOT.(Bulk Only Transport) BOT is the most common protocol. BOT is not what you want in a USB3.0 storage device, but you need to find units that support both SATAIII(6GBs) internally and UASP. UASP uses bi-directional communication and the packet size is much greater. Turbo mode is not the same as that just increases the packet size but is not a bi-directional parallel protocol. UASP also uses less CPU processes and has a lower overhead.
Finding multi-bay units that have UASP enabled is difficult and if it does not specifically say it is UAS(P) in the specs, it will be BOT only.
You kind of left out PCIe and flash storage. Up and coming speed champ.
Even TB2 only uses 4 PCIe lanes, so direct PCIe storage cards are faster. My own speculation is that Apple will introduce a new MP based Haswell with both cards having flash storage. Haswell will also natively support USB3(.1?) and more PCI lanes. We’ll see.
My thanks, Greg