While HD video files are significantly larger than audio files, it's actually this fact that makes them more suitable for (or, indeed require) RAID storage, because a RAID system is really good at providing a large amount of sustained bandwidth. At a recent Apple press event, I saw an impressively large number of HD video streams being played back on a Mac Pro (using the internal volumes in a RAID 0 configuration) that previously would have required a separate storage system such as an Xserve RAID. The first thing to remember is that audio software, in general, tends not to benefit from RAID technology in the same way as, say, video. not the boot disk), but is this the maximum performance attainable from the Mac Pro's internal storage? What about using the software RAID features we just discussed? This Mac Pro test chart shows the number of stereo, 44.1kHz/24-bit audio tracks that could be played back simultaneously in Logic Pro, using a single drive, and also with two and three drives in a RAID configuration.In the above test, I was recording and playing back from one drive that was dedicated to audio (ie. Finally, the maximum number of playback tracks possible was 101. Scaling back the number of record tracks, it was possible to record six tracks while playing back 96. Recording 12 tracks while playing back 84 tracks was fine, but recording 12 tracks with 96 playing back resulted in the Core Audio error 'Disk is too slow or System Overload'. I recorded 12 stereo tracks at a time and then repeated the test, incrementing the number of tracks playing back simultaneously, as I recorded more additional sets of 12 tracks. To test the Mac Pro's internal storage system, I used Logic Pro with an RME Fireface 800 audio interface to record stereo, 24-bit, 44.1kHz audio files to a single drive. However, OS X's software RAID does, in fact, work with all Macs and all drives, although you'll get the best results using internal drives or external SATA drives. And since Intel also manufacture RAID controllers, this is one area that might be useful to Apple in the future. In a RAID 1 system (aka Mirrored RAID Set), data stored on one drive is literally mirrored on another so while RAID 0 offers performance without redundancy - if one drive fails you're completely screwed - RAID 1 offers no performance increase but provides complete redundancy, because if one drive fails, you have a completely mirrored backup.Īs a side note, it's worth pointing out that while this software RAID functionality is good to have in the Mac Pro, other workstation manufacturers often provide a hardware-based RAID facility, in the same price range, that supports additional RAID modes. As a simple example, if you have a RAID 0 array with two drives, theoretically it takes half the amount of time to read and write an item of data compared with one drive, because half the data is stored on the first drive and half is stored on the second, and the read or write happens on both drives at the same time. In a RAID 0 system (aka Striped RAID Set), single items of data are split across all disks in the array, which increases the overall data throughput because you now have multiple drives reading and writing simultaneously. Now click Create and the RAID volume will be created. Simply drag the drives you want to include in the RAID volume into the box in the lower half of the RAID panel, enter a name, check the format for the volume, and choose the RAID Type. OS X offers two modes of RAID functionality - 0 and 1 - that can be configured in the RAID tab of Disk Utility (Applications / Utilities), as shown in the screenshot above. But what exactly does this mean? And does it offer any benefits for audio performance? OS X & RAID One potentially useful aspect of having this much internal storage across multiple drives is that you can take advantage of OS X's RAID functionality to use the multiple drives as a single volume. This new storage system is well suited to those who work with large amounts of audio. If you've done any research on the Mac Pro (or have read this month's review, starting on page 124), one thing that might have caught your eye is the fact that, as in the case of the old Power Mac G4, you can install four internal SATA drives in the chassis - and it's easy to swap the internal drives in and out of different Mac Pros. With the new Mac Pro offering increased internal data storage, we investigate whether using the software RAID functionality built into OS X has any benefits for audio applications. Here you can see I have one internal drive as a boot drive and the other three drives in a RAID 0 configuration to test as a volume for audio work. Apple's Disk Utility provides software RAID functionality, allowing multiple drives to be configured as a single volume.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |