Storage requirements very considerably depending on key decisions made in the preproduction process. What will be the standard frame rate? Bitrate? Is it a multi-cam shoot? How many hours of footage? What codec? Answering these questions is crucial to any shoot. But, does shooting 4K mean you simply multiply the storage by 4x? Not necessarily.
Many codecs exist to edit in 4K – but they are not created equal. 4K RAW and uncompressed formats take up more storage, and require faster drives with faster connections. Compressed 4K takes up less storage and bandwidth, but the computers need to be much more powerful to handle the images. In addition, multi-camera edits require pulling multiple video streams from the SAN or NAS. We decided to look at the top questions people should consider when choosing 4K storage.
What is the best way to determine the amount of storage required for a 4K shoot?
Before making the decision to shoot 4K on your next project, it would be wise to first calculate the total GB or TB of storage required. The good news is our partner AJA created an app, called AJA DataCalc, that can calculations for you. Remember, storage requirements grow rapidly depending on bitrate & codec choices made in acquisition or post.
If you're dead set on manually figuring out the numbers, it's not hard either. Here's an example of the formula:
- Approx. bit rate / 8) x 3600s = KB per hour / 1000 = GB (Gigabytes) per hour
Explained: Approx. bit rate / 8(converting Megabits to MegaBytes) x 3600s (seconds in an hour) = KB per hour / 1000 = GB (Gigabytes) per hour
- GB per hour x hours of operation per day (count all cameras!) =GB per day
- GB per day x requested period of storage = Basic RAW storage required (*+40%)
*Notes: render files and other associated media will increase your storage needs. If your storage is RAID formatted, some of your storage may be unavailable due to the protection RAID formatting offers. Lastly, many storage solutions see performance dips if more than 80% of your storage is full. Key Code Media recommends that using the above formula still requires an additional 40% extra storage space. For more information, see: http://michaelkammes.com/storage/choosing-the-right-shared-storage-solution-part-1-of-3-bandwidth-connections/
Before figuring out the numbers it's best to find answers to the following questions:
- Amount of cameras
- Number of hours cameras will be recording
- Frames per second recording
- Image resolution (HD, 2K, UHD, 4K, 6K, etc.)
- Video compression type used: RED RAW, DPX, XAVC, ProRes, DNxHD,etc.
- How long data must be stored
- Offline / online workflows will require additional storage for the proxy media.
We highly recommend using the AJA DataCalc App when first estimating the amount of storage space needed on a project. DataCalc is able to estimate storage needed factoring in the amount of hours, video resolution, audio formats, and codecs being used. Did we mention it's free?
Is it possible to edit 4K in a shared storage environment?
Absolutely! Traditional editorial departments rarely edit only in uncompressed or lightly compressed camera formats, such as uncompressed, DPX, and RAW. The additional expense in storage solutions to edit this way would far exceed the benefits. Instead, most people would recommend keeping a high-res master (& back up), then do all the editing in a lower-res proxy. This offline / online workflow has been around since the first NLE, and will no doubt be essential to many workflows for the foreseeable future.
The recent announcement of Avid's DNxHR, a resolution independent codec, will allow people to edit in resolutions above HD – including UHD and 4K, and paves the way to edit in even higher resolutions inside Avid Media Composer. DNxHR is compressed, relieving storage space, but may require more GPU processing from the editing workstation.
If you are looking to edit an entire project with uncompressed or lightly compressed media, even the most high-end storage currently limits editors to 1, and rarely 2 streams of uncompressed/raw. That means, only one editor will be able to access high-res media from the system. This is a big reason why new compressed codecs, such as DNxHR & the new flavors of ProRes, will be so important to editing 4K.
Do I need solid state drive (SSD) to edit 4k?
Solid State Drives certainly offers great speeds for boot drives & project drives, and offers fantastic speeds for data movement.
SSD storage – SAN and NAS included can be many times more expensive than traditional spinning hard drives. For smaller projects, SSD drives are a great solution. But if capacity is of paramount importance, SSD may not be your best choice.
What are the minimum storage requirements for 4K editing?
Be aware of minimum requirements to consider when choosing shared 4K storage, such as throughput, connection, etc. For example, choosing incorrect spindle speed could leave your editor with a very unpleasant editing experience. Here are some bare minimum requirements to consider:
Connection – 1GigE minimum. 10GigE or 4/8/16 Fibre recommended
NLE/Finishing Support – Your NLE needs to handle the codec you are onlining and/or offlining with. If a finishing system, the system needs to handle the EDL from your NLE. The NLE also has to allow media to be utilized from shared storage.
Speed – 7200rpm (rotational speed) minimum! Stay away from green drives, or other power saving drives. These drives can spin down to conserve power, but can cause playback issues within your NLE.
Throughput – (Your codecs data rate/8) x amount of concurrent tracks with video in your NLE = MB(MegaBytes) per second. This number must fit within the speed provided by your Ethernet or fibre connections. Key Code media recommends a 25% overhead to account for real world throughput values.
How many streams of 4K can be pulled from my storage?
The amount of streams than can be pulled from a share file system is heavily dependent on what file formats you're using. Using DPX, RAW, or uncompressed? You'll get less streams of these formats than compressed streams. These formats typically have huge file sizes, and require lots of bandwidth.
ProMAX Platform Stream Count Performance (By Codec):
How much more does 4K storage cost?
Numbers can vary wildly –depending on the quality of the drive, if it's meant for enterprise or home use, and if it's an off the shelf single drive, or provided by a storage manufacturer. If we look at drives which are rated for professional use, the rule of thumb for storage cost is $1.20/GB for SSD, and $0.75/GB for a spinning disc. While 4K media does not necessarily mean 4x cost of HD, there is a significant increase in cost of storage.
According to Vidiomaker, " One hour of standard definition DV footage requires approximately 12.7GB of storage; approximately 217MB per minute. By comparison, one hour of RAW 4K content requires close to 110GB of storage; approximately 2GB per minute." Assuming that's correct, you're looking at around $1 per minute, per camera.
With hundreds of vendor choices, it becomes easy to get lost in all the various techinical details when selecting video production storage. Specific choices like volume locking or file locking, SAN or NAS, and RAID types will likely shape the way your video production operates. Learn more about how Key Code Media can help you make the right storage choices for your given workflow. Click here