Reality Check: What Does a 4K Production Workflow Require?

What Do Mid-Sized 4K Data Rates Mean for Capture and Transfer?

I shoot 4K DCI with my Panasonic GH4 and ithe data rate averages 80 Mbps. That's a data rate of 10 Megabytes per second (MB/sec). A decade ago, I was reading and writing to my FireWire 400 drives at more than 20 MB/sec. A single laptop "pocket" drive in a bus-powered USB-3 enclosure will easily do over 100 MBps. So do you need 1000 MBps of Thunderbolt-2? No. You don't.

This 7200 RPM HGST Touro S Pocket Drive will comfortably handle 4K transfer rates via USB 2.0 (480Mbps) or USB 3.0 (5Gbps).

Similarly, when Panasonic had only the GH2 camera (which held its own against the big boys in Zacuto's Revenge of the Great Camera Shootout), it was hacked to record at above 100 Mbps instead of being limited to the out-of-the-box 28 Mbps. The importance of fast cards became paramount. When the camera needed to "span" clips (finish writing one 4GB file while simultaneously starting to write video into the next file), if the card wasn't fast enough, the camera simply stopped recording. The SanDisk Extreme Pro 95 MB/sec cards proved the most reliable cards.

A SanDisk Extreme Pro 280 MB/sec card

When the GH4 was announced to have a 200 Mbps data rate for HD, and that it was the first DSLR to support the UHS-3 specification (faster total speed, minimum of 30 MB/sec requirement for the cards) speculation began to swirl as to whether the camera would not work with slower UHS-1 cards. Well, the camera is now shipping and everyone is recording 4K just fine with any number of UHS-1 cards, even those cards only touting 45 MB/sec are recording 4K till the card is full, without issue.

This 4K is only averaging 80 Mbps, 10 MB/sec. Can you existing HDD handle this? It most probably can.

Editing Software

The next question is whether your edit software can handle the larger frame size. Does your software require you to transcode camera footage to a more editable format? Or can it handle LongGoP H.264 or AVCHD directly in the timeline? For those of you still editing with Apple's old Final Cut Studio products, the answer is clear: It's time to move on.

Apple Final Cut Pro X, Adobe Premiere Pro, Sony Vegas, Grass Valley EDIUS, Avid, and more, all handle 4K footage just fine. Moreover, some applications leverage the GPU quite effectively to spare you from ever having to transcode your footage. You edit with the camera original clips right in the timeline. This leans the data rates stay low.

Choosing a transcode option in FCP

FCP X does have a preference to transcode the footage in the background to a more editable format, usually ProRes, and this will dramatically increase the bandwidth your 4K footage needs. Thankfully, this feature can be turned off. It also saves on hard drive space because you're more than doubling up the file size. The ProRes may take as much as 4x the size as your source footage. And depending on the number of projects/ amount of footage you keep on your drives, that means you'll need more storage, and faster storage as well.

I use Premiere Pro CC and I have had no trouble dropping my 4K source files into a 1080 timeline on my PC and cutting what looks like a three-camera, two-person interview (shown below) out of footage from a single 4K camera shoot. If your PC is fairly recent, with an i7 processor, a good GPU with at least a GB of RAM, and your computer has at least 8 GB of RAM I think you should be fine. If it's older, like a Core 2 Duo, i3 or i5, then you may consider upgrading.

I chose to get a "gaming" PC (the Alienware shown below) because it was centered around cramming as powerful a GPU into a case as possible. I also wanted to get something that could easily fit into a standard rack of video gear. I found the Alienware X51 witch fits those requirements. It's not the most powerful PC. It's not the biggest GPU and doesn't have multiple GPUs. In fact the one GTX card fills the available space inside the rather slim case. But, based on my experience with my edit machines, I know I'm not going to expand the computer. I just need it to chew through video. And this machine does that just fine.

An Alienware X51 gaming PC makes a fine 4K editing machine.