Q: “What are the differences between audio storage needs for digital audio and digital audio?”
A: Although audio and video are often thought of together as “A/V”, they are truly different animals when it comes to digital storage. Audio and video have different data transaction requirements, and therefore each have their own storage needs. Because of the relatively small size and large number of files pushed through the system in many audio applications, processing digital audio becomes very per instance, or transaction intensive. By comparison, video applications usually require extremely high bandwidth due to the constant demand for a smaller number of much larger files.
The actual rotation speed of the platters in a hard drive is extremely important to digital audio storage performance. The key here is, the faster the RPM the better. Anything less than 7200 is going to yield less than desirable results (10K & 15K is even better), i.e. less tracks, etc. Why? Well, again, several smaller files are written to sectors across the platter, and over the course of your project these files become noncontiguous. The heads have to move back and forth across the platters to write and read the scattered data. Think about the number of punch ins, edits, and takes you have on one track – now multiply that times all the tracks you use (lets say 24) – that’s a LOT for a hard drive to deal with, and a LOT of traveling for the heads.
On average, Video files are much larger than audio files. Bandwidth refers to the amount of data that can be transmitted in a fixed amount of time, and often is described in megabytes per second (MB/sec). Bandwidth is more important for video than spindle speed because of the way video NLEs access files. NLEs create large files comprised of detailed pixel/color information. These files require a big pipe to flow through at speeds fast enough for the video NLE to process. So, the key here is bandwidth – the wider the pipe the better!
Generally speaking, rotation speed and bandwidth affect the performance of both digital audio and digital video. However, rotation speed is more important to the effectiveness of digital audio storage and bandwidth is more important to the performance of digital video. There’s obviously more to this conversation than what we can cover here including the benefits of RAID, the use of several hard drives in one DAW (Round Robin recording), SCSI vs. FireWire, USB 2 and more. Stay tuned to inSync in the future (and many articles from the past) for more information.