Speed Requirements of Video Editing Storage

“Fast is much faster than Slow, but Darned Fast isn’t much slower than Darned Fastest.”
(Adam Wilt, Nov. 7, 2023)

We all know that video editing requires significant computer  and storage performance. But how fast is “fast enough?” In truth, the speed of your computer is less important than the speed of your storage. Almost every computer released today can edit video. Yes, a faster computer will render and export faster, and stream more multicam angles, but, regardless of computer speed, the image and audio quality will be the same.

These days, performance is much more dependent upon storage and how it is connected than the computer. The problem is that, all too often, we don’t know what speeds we need nor the speed of our storage. In other words, we are operating blind and hoping “everything works.”

The purpose of this article is to illustrate performance fundamentals so that you can better decide whether the gear you have is sufficient for the task, or if you need something faster. While all NLEs handle media a bit differently, they are all constrained by the same speed limits.

DEFINITIONS

• Bandwidth is the speed data transfers to (write) and from (read) storage to your computer. This speed is measured in MB/s (megabytes per second).
• Capacity is the amount of data a piece of hardware holds. It is measured in gigabytes (GB).
• Storage can be inside your computer (internal) or an outside unit connected to your computer by a cable (external).
• 1,000 MB = 1 GB.  1,000 GB = 1 TB (terabyte). These are marketing numbers, engineers use a slightly different conversion of 1024.

STORAGE SPEEDS

Let’s start at the beginning. While there are variations in hardware speed, this chart shows the relative differences between the gear. This also shows the approximate speed limits of USB-3 (5 Gbps), Thunderbolt 2 (20 Gbps), and Thunderbolt 3/4 (40 Gbps).

NOTE: Codec bandwidth is often expressed as “bps” (bits per second, lower case “b”), while storage bandwidth is commonly expressed as “Bps” (Bytes per second, capital “B”). To convert from “bps” to “Bps”, divide “bps” by 8.

While hard disk drives (HDD) have far more capacity, solid-state drives (SSD) are far faster. Also, SSDs are preferred for multicam editing because they don’t have the latency (delay) that HDD drives and HDD RAIDs do.

There are two principle types of SSDs: SATA and NVMe. SATA is older and slower. NVMe SSDs are about six times faster than SATA SSDs.

Now let’s look at single camera – as opposed to multicam – editing. This chart illustrates how different codecs require different amounts of bandwidth. This chart uses 1080p/30 fps media as its example. (If you are editing 4K media, multiply the editing bandwidth by 4.)

NOTE: Editing bandwidth illustrates the speed necessary to play two clips of the same format media at the same time without rendering. For example, playing B-roll over a talking head.

It is important to note that while H.264 media can be edited on all modern computers and uses smaller files, it is more CPU intensive, has a more restricted color space and tends to take longer to render or export.

In addition to which codec you use, there are two other factors that significantly affect storage: source media frame size and frame rate. Let’s start with frame size.

Storage requirements increase dramatically as frame size increases. This is most clearly illustrated when you jump from editing 1080 to 4K. It is important to mention that these numbers are for just a single stream of video. When planning “normal,” single-camera editing, a good bandwidth guide is to double these numbers.

NOTE: While these numbers change when editing media using different codecs, the speed relationship is similar. Larger frame sizes generate larger files.

Storage bandwidth also increases dramatically as frame rate increases. These numbers, like frame size, are for a single stream of media. When planning “normal,” single-camera editing, a good bandwidth guide is to double these numbers.

NOTE: While these numbers change when editing media using different codecs or frame sizes, the speed relationship is similar. Faster frame rates generate larger files.

When we move to multi-camera editing, storage speeds and low latency become especially critical. This chart shows the differences between editing proxy files at 50% resolution of 4K source media vs. editing the 4K source media itself.

NOTE: The number of multicam streams an NLE can actually edit varies by NLE.

It is also important to point out that the latency (delay) inherent in all spinning hard drives – due to the time needed to move the heads from one place on the disk platters to another – means that SSDs are vastly preferable for multicam edits containing more than a few cameras.

NOTE: While H.264 generates much smaller files, this format is especially difficult to edit in multicam. Based on past tests with both Premiere and Final Cut, editing using ProRes more than doubles the playable streams when compared to editing native H.264 media.

Direct-attached storage is preferred for media editing because it is optimized for speed. However, network-attached storage (NAS) is preferred when you need to share media between multiple editors. Sadly, it is also far slower. Even if you have a fast switch providing faster bandwidth, most servers don’t have the speed to fill a high-speed Ethernet connection.

The two yellow limit lines indicate the approximate maximum speed that a 4- or 8-drive RAID can sustain. For example, if you connected a 4-drive RAID 5 into a 10G network, even though the network supports up to 1 GB/second, the RAID can only supply up to 500 MB/second; far less if multiple users access the same server at the same time.

RELATED ARTICLES

• Here’s an explanation of what RAID “levels” mean.
• Here’s an illustration of the differences in speed between different RAID levels.
• Here’s Apple’s ProRes White Paper, an excellent resource for bandwidth and ProRes information.
• This article explains real-world factors that affect HDD and SSD performance.

REAL-WORLD RESULTS

The charts above provide theoretical speeds. Now let’s take a look at single camera editing results measured in the “real-world.”

NOTE: Drives were tested using Blackmagic Disk Speed Test (v. 3.4.2). Green checkmarks indicate speeds fast enough to edit that frame size, frame rate and codec.

USB-A HARD DISK DRIVE

Green checkmarks indicate the storage is fast enough to read or write that specific media.

This is a very slow USB-A hard disk with read and write speeds below 100 MB/second. (It is normal for read and write speeds to vary; sometimes by a great deal.)

Even a slow drive like this can easily edit all 720 and 1080 single camera video formats. However, this drive is too slow for multicam editing.

FRAME SIZE COLOR KEY

• Yellow bracket: 720 and 1080 HD
• Blue bracket: UHD and 4K
• Green bracket: 8K

4-DRIVE HDD RAID 5

This is an older and slower HDD RAID 5, but even these speeds support all HD and 4K single camera editing. Within limits, meaning 2-4 streams, you could also use this for small multicam edits.

SATA SSD DRIVE

Stepping into the world of SSDs, a “slow” SATA SSD still supports all HD, 4K and some slower frame rate 8K video; that is, at 24 or 25 fps media.

In addition, unlike spinning media, SSDs have essentially no latency. This means a single SATA SSD, connected via Thunderbolt 3/4, could easily support twenty ProRes Proxy streams (50%) of 4K video for multicam editing.

3-DRIVE NVMe SSD RAID

Stepping up in speed, a 3-drive NVMe SSD RAID transfers data at over 2 GB per second. This is more than enough for all video formats – and it is especially useful for multicam editing; even those containing more than 20 streams of any video format.

M2 MAC STUDIO INTERNAL DRIVE

Just as an example of the current high-end of storage speed, the internal drive of a Mac Studio delivers data around 6 GB per second!

While excessively fast for any single camera edit, this delivers more than enough speed to support 8K multicam editing; up to 11 streams!

SUMMARY

What these fundamentals show is that the simple act of importing, previewing and editing video does not require excessive computer or storage resources, though increasing frame size or frame rate impacts storage bandwidth.

Where more power is required is when we start to manipulate individual pixels or process multiple streams of video. For example, color grading, effects, rendering, compression, export and multi-camera editing. In these instances, faster computers handle these tasks more easily.

So, really, the key question becomes: “How much are you willing to spend to go faster?” That answer varies for each of us.

GOING FURTHER

Now that you understand the fundamentals of storage, this collection of reports highlights the performance you can expect from current Apple systems. They also provide guidance on optimal configurations that balance speed with budget.

MacBook Pro

• Configure a 2021 M1 MacBook Pro for Video Editing
  (The advice here is also the same for M2 systems.)

Mac mini

• M2 Mac Mini: Performance Tests & Reviews

Mac Studio

• M2 Mac Studio Performance Tests for Adobe Premiere Pro
• M2 Mac Studio Performance Tests for Apple Final Cut Pro

Mac Pro

• M2 Mac mini, Mac Studio or Mac Pro – Which to Pick?

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