COMPUTER HARDWARE & STORAGE
Computer hardware is one of the main barriers of producing a 4K workflow from capture to exhibition. Most of this is due to data bandwidth requirements, which depend on:
• The codec—the method of compression of all the bits the camera takes into a smaller format for recording.
• The frame rate—frames per second. For example, using the Sony F65 in 4K RAW mode (16-bit linear, F65RAW-SQ) at 24 fps requires approximately 300+ MB/s; 4K ProRes 4444 at 24 fps = 141 MB/s.
According to Jess Hartmann, CEO of ProMAX Systems (www.promax.com), the issue with most computer workstations working in 4K is disk storage speed. "A typical spinning disk drive can transfer data at a maximum of about 80 MB/s," he explains. "Considering everything else happening on the computer, you can count on about 50 to 60 MB/s. So to work in 4K most of the time, you need an attached RAID array, fast SAN storage or onboard SSD drives."
We all know that 4K has four times the image information of full HD, and in terms of data, this also applies. Although storage prices have come down significantly over the years, it’s still a concern. A workstation without fast disk storage options still will need to transcode uncompressed 4K down to a smaller, intermediate format in order to edit. But even when transcoded to a 422 codec like Apple ProRes or Avid DNxHD, 4K files still can fill up your hard drive quickly. For example, one minute of ProRes 422 (1920×1080) HD material yields around 1 GB, while one minute of 4K ProRes 422 yields roughly 4.25 GB. This is one of the main reasons why projects are still being delivered in 2K or 1080, for the most part.
"As an example, the trailer for The Amazing Spider-Man is approximately 500 GB in size—and that’s compressed 4K video," explains Philip Parian, PROMISE Technology’s product marketing specialist (www.promise.com). "You can only imagine just how much storage someone who’s working on a full-length movie in uncompressed 4K would need. With the introduction of Thunderbolt 2 hardware RAID storage capabilities for prosumers with the Pegasus2 and the 4K editing and scalable storage features of the PROMISE VTrak A-Class, prosumers and professionals alike are given access to all pieces of the 4K workflow, from ingestion to postproduction."
PROMISE Technology is one of the leaders of high-performance RAID systems in the post-production industry. Their new Pegasus2 drive is a popular storage drive that many productions are employing after data is offloaded from the camera’s recorder. The drive is Thunderbolt 2-enabled, allowing the D.I.T. to transfer 4K content at lightning speeds. The drives are optimized for 4K because they offer the maximum amount of throughput for a portable, direct-attached workflow.
"On average, working with 4K content requires around 15 GB/s connectivity," says Elaine Kwok, product marketing manager for PROMISE Technology. "With PROMISE Pegasus2 allowing for the maximum amount of throughput for Thunderbolt 2, which boasts 20 GB/s connectivity, the ability to work with 4K is now available to the masses and not just big production studios."
As 4K becomes more ubiquitous, we’ll see more storage manufacturers advancing their products to accommodate the speed and capacity requirements of filmmakers. For example, G-Technology (www.g-technology.com) is a storage company, and their stand-alone G-Technology G RAID with Thunderbolt products (4 TB and 8 TB) were specifically conceived for the needs of professional content creators.