Friday, August 22, 2008

FireWire Fine Print

QUESTION: What kind of back up drive for Pro Tools should I use?

In this installment, I will talk about the wonderful world of back up drives for Pro Tools, which can get very convoluted. Recently, we had a couple of incidents (all within a week) where clients came in with drives that were either not formatted properly or were unusable. As a disclaimer, I urge you to examine the documents listed at the end of this article as your final reference to make sure you have the information that applies to your particular situation.

In the labyrinthian Digidesign Web site, there are several Web pages and PDF documents that spell out in mind-numbing detail what you can and cannot use with Pro Tools. I’d like to mention a few items from these documents that you may not be aware of. Most of our discussion will be limited to Pro Tools|HD and Pro Tools|HD Accel Systems (with Pro Tools 6.9.2 or higher). We use Apple computers as our Pro Tools platform as do many people in our industry.

The popular back up medium of choice today is external FireWire drives. USB drives may be okay as a file transfer or storage medium, but they are not supported for record and playback in Pro Tools. With the proliferation of many cheap drives, you have to be mindful of the quality and reliability of the drives you select as well as some basic specifications. When looking for a FireWire drive, here are some things you should look for.

  • We recommend you get a FireWire 800 drive for faster data transfer speed (vs. FireWire 400). Most drives today support both interfaces.
  • Does the drive (either FireWire 800 or FireWire 400) use the Oxford 912 or 924 chipset interface? This may be difficult to find out, but that is what Digidesign specifies.
  • Does it have a cache size of 8MB or larger? That would be the preferred drive cache to get the best performance from the drive mechanism.
  • Does the drive spin at 7200 rpm or faster? Again, this is for better performance.
  • Is it a RAID drive? Pro Tools does not support RAID technology.

Here are other tips you should follow / know:

  • Drives must be dedicated for audio.
  • FireWire 400 and FireWire 800 drives should not be combined. We haven’t tried it to see what happens, but Digidesign used bold font emphasizing this point, so it can’t be good.

The brand of drives used by some of our clients includes Glyph, Lacie and Avastor. It is customary for clients to purchase back up media from the studio. The primary reason for this is so that you will be using a brand that we are familiar with and have used many times. No drive is obviously crash proof, but we try to provide you with a drive that has a pretty good track record throughout our sessions.

If you have to format your FireWire drive for your session, make sure you use Mac OS Extended (HFS+, Journaled). In addition, the "Install Mac OS 9 Disk Driver" option should be selected when formatting the drive. This will ensure extended backward compatibility with older Mac operating systems. There is no performance or compatibility penalty for choosing this option. One of the problems we saw recently was that a client had formatted their drive using the NTSF format. The client came in with data on their drive. Luckily, we were able to read the data and transfer the data, but we had to reformat their drive since you cannot record and play back in Pro Tools under that format. We will format the FireWire drive that we supply so you don’t have to worry about it.

On a session where you will be using Pro Tools, we will typically set it up so that your session files will be on one of our hot-swappable, high performance SCSI drives. The reason for this is for data performance, particularly if you are using high sample rates and/or large number of tracks. Yes, we have done sessions accessing files directly on the FireWire drive, but we prefer to optimize for maximum responsiveness so you don’t lose anything during the session, especially if it is a tracking session. This means that at the end of your session, files will have to transferred from our SCSI drive to your FireWire drive so make sure you account for that time.

On a final note, a FireWire drive, like any hard drive, has a limited lifespan. A common measure as given by manufacturers is MTBF or mean time between failures. A good discussion about MTBF and other hard drive specifications is presented at the Web site. It will not be duplicated here. Sometimes, it is not very easy to find MTBF and other product specs in the manufacturers’ literature. It is best that you treat the drive as if it has a limited life expectancy (especially if you drop it). This means you should make a safety copy, preferably on a different type of medium (e.g. AIT-tape) and store copies in separate locations. We talked about how safeties can save your hide previously.

Here are some of the resources referenced in this article:
Digidesign: FireWire Drive Requirements on Mac Systems
Digidesign: Pro Tools Storage Guide
Digidesign: How do I move sessions between Mac and PC Mean Time Between Failures (MTBF) Service Life

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