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appendix a
Connecting SCSI Drives
SCSI hard drives are the recommended recording media for Pro Tools TDM systems on Windows, and can also be used with Pro Tools on
Macintosh.
Although Pro Tools will let you record to your system drive, this is generally not recommended. Performance for recording and playback on system drives is sometimes worse than on non-system drives, resulting in lower track counts and fewer plug-ins.
Be aware that recording to your system drive can quickly use up available hard drive space. This can negatively affect system stability and the performance of all applications including Pro Tools.
For the most current information on hard drive requirements and recommendations, see the compatibility pages on the Digidesign Web site
(www.digidesign.com/compato).
SCSI Requirements
For maximum recording and playback performance, Digidesign recommends qualified SCSI hard drives and a qualified SCSI host bus adapter (HBA) card or (on Windows systems) a qualified built-in SCSI HBA connector on the motherboard.
SCSI drives must provide a data transfer rate of at least 9 MB per second of sustained throughput.
Visit the Digidesign Web site (www.digidesign.com) for a list of qualified SCSI hard drives and SCSI HBA cards:
Software RAID is not supported for audio drives.
Appendix A: Connecting SCSI Drives
97
SCSI Cables
Use shorter SCSI cables to improve reliability.
Table 1 provides guidelines for maximum cable lengths according to SCSI type.
In the following table, the maximum cable length includes all cables used in the chain, not just point-to-point connections.
Table 1: Maximum cable length and number of drives supported according to SCSI type
SCSI type and transfer rate maximum cable length maximum # of drives
3 meters 8 Fast SCSI
10 MB/sec
Wide SCSI
20 MB/sec
3 meters 16
3 meters 5 Ultra SCSI
20 MB/sec
(8-bit narrow)
Ultra SCSI
40 MB/sec
(16-bit wide)
Ultra SCSI
20 MB/sec
(8-bit narrow)
Ultra SCSI
40 MB/sec
(16-bit wide)
Ultra2 SCSI
Low Voltage Differential (LVD)
80 MB/sec
3 meters
1.5 meters
1.5 meters
1.2 meters
5
6–8
6–8
16
16-bit resolution requires about 5 MB per minute. Stereo tracks require about twice as much hard drive space. Sample rate also affects hard drive requirements.
Using these guidelines:
• 192 mono tracks of 44.1/48 kHz, 24-bit audio takes up about 1453 MB (44.1 kHz) or
1584 MB (48 kHz) of hard drive space per minute.
• 128 mono tracks of 44.1/48 kHz, 24-bit audio takes up about 969 MB (44.1 kHz) or 1055 MB
(48 kHz) of hard drive space per minute.
• 128 mono tracks of 44.1/48 kHz, 16-bit audio takes up about 646 MB (44.1 kHz) or 703 MB
(48kHz) of hard drive space per minute.
• 64 mono tracks of 88.2 or 96 kHz, 24-bit audio takes up about 969 MB (88.2kHz) or 1055
MB (96kHz) of hard drive space per minute.
• 64 mono tracks of 88.2 or 96 kHz, 16-bit audio takes up about 646 MB (88.2 kHz) or 703
MB (96kHz) of hard drive space per minute.
• 24 mono tracks of 176.4 or 192 kHz, 24-bit audio takes up about 727 MB (176.4kHz) or 791
MB (192kHz) of hard drive space per minute.
Disk Space for Audio Tracks
A single mono audio track recorded at 24-bit resolution at a CD-fidelity sampling rate of
44.1 kHz requires about 7.5 MB of hard drive space per minute. The same track recorded at
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Getting Started with HD
Distribute Audio Across Multiple Drives
For best recording and playback performance, don’t record and play back all audio files in a session from the same drive. Instead, use
Pro Tools Disk Allocation features to distribute audio files between multiple drives. See the
Pro Tools Reference Guide for details.
Separate Video and Audio Files
If you are working with QuickTime, movie files must reside on a different SCSI bus than audio files. If audio files reside on disks connected to a
SCSI HBA card, video data should reside on drives connected to a different SCSI bus.
Dual-Channel SCSI HBA Cards
If you use a dual-channel SCSI HBA card, allocate audio files equally to drives connected to each of the two busses on the card for optimal performance.
If using video files, make sure to put your video files on one bus and audio files on the other bus.
5
Verify that the last SCSI device in the chain is
properly terminated. (See “SCSI Termination” on page 100.)
6
Attach power cables to the hard drives.
SCSI accelerator card to SCSI hard drive
Connecting a SCSI cable to a SCSI HBA card
Connecting SCSI Drives
To connect an external SCSI drive:
1
Turn off power to both the computer and the hard drive.
2
Attach a SCSI cable from the SCSI port of the hard drive to the SCSI port of the SCSI HBA card or computer.
3
Secure the cable’s connectors to the hard drive and computer.
4
Connect additional drives by daisy-chaining from one drive to another. Keep cable lengths to a minimum (see Table 1).
to SCSI accelerator card
Connecting an external SCSI hard drive
Appendix A: Connecting SCSI Drives
99
SCSI Termination
Your computer’s SCSI chain must be properly terminated or your system will not function correctly. Only the last device on the chain should be terminated using the termination type recommended by the hard drive manufacturer.
The drive should use either an external terminator plug or have its internal terminators enabled. If you are using a terminator plug, Digidesign recommends that you purchase and use an
active terminator.
Do not enable internal termination and install an external terminator plug on the same drive. This will cause SCSI errors. See your hard drive’s documentation for information on which type of termination it uses.
Windows Requirements
SCSI hard drives used for audio recording on
TDM systems must be formatted for the FAT32 or NTFS file system. Under Windows 2000 and
Windows XP, NTFS drive partition sizes are almost limitless, whereas FAT32 drive partitions have a limit of 32 GB.
TDM Windows systems require that you use Microsoft Windows Disk Administration software for drive formatting and partitioning. Use only one disk utility for all drives in a system.
Quick Formatting SCSI Drives
Macintosh Requirements
On Macintosh systems, SCSI hard drives used for audio recording on TDM systems must be formatted (or initialized) for either the HFS+ or
HFS file system (HFS+ is recommended). Drive partitions of up to 2 terabytes (2000 gigabytes) can be used.
TDM systems require that you use the Apple
Disk Utility (Mac OS X) or ExpressPro-Tools
(Mac OS 9) for all drive formatting and partitioning. Only one disk utility should be used for all drives in a system.
Initializing a Macintosh Drive
To initialize a new Macintosh drive:
1
Turn on your hard drives, computer, and any other peripherals.
2
Do one of the following:
• With Mac OS 9, use the ExpressPro-Tools software utility included on your Pro Tools
Installer CD-ROM to initialize and partition any new hard drives.
• With Mac OS X, use the Apple OS X Disk
Utility to initialize and partition any new hard drives.
For details on using disk formatting utilities, refer to their online documentation.
Initializing a Windows Drive
To format a new Windows drive:
1
Turn on your hard drives, computer, and any other peripherals.
2
Use Microsoft’s Disk Management software, located in the Administrative Tools Control
Panel under Computer Management > Storage.
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Getting Started with HD
Refer to your Windows documentation or help for information on how to use the Disk Management software.
General Hard Drive
Maintenance
If using Macintosh drives on Windows sys-
tems, refer to“Using Macintosh Drives on
Formatting Drives
There are two different types of formatting: high-level formatting and low-level formatting.
Digidesign does not recommend low-level formatting.
High-Level Formatting (Initialization)
High-level formatting, or initializing a drive replaces the drive’s directory, volume partition map and drivers. Information about the drive is created and drivers that communicate this information to the host CPU are installed. The drive itself is not erased, nor is verification performed.
When is High-Level Formatting Necessary?
It is generally necessary to high-level format a hard drive in one of the following cases:
◆
If a new drive is being prepared for use on a computer for the first time and the drive is not already high-level formatted.
◆
If you suspect that the directories containing the drive’s information have become corrupted.
◆ If a drive is being changed from one platform to another. For example if you are switching from a Macintosh to a Windows-based system, or from a Windows to a Macintosh-based system, the drive must be high-level re-formatted for the new operating system.
Low-Level (Physical) Formatting
Low-level formatting means completely erasing the hard drive and rewriting each sector address on the drive. In low-level formatting, the sector and track addresses, error-correction codes, and other details are written on the platters of the hard drive in the form of a magnetic pattern. A low-level format permanently erases all data on the drive.
When is Low-Level Formatting Necessary?
Virtually all hard drives come pre-formatted from the manufacturer. Low-level formatting is generally unnecessary except in rare circumstances. They are:
◆
If you want to change the Block Size of the drive. This is not recommended by Digidesign.
Digidesign systems only recognize 512-byte blocks.
◆
If you want to perform permanent deletion of data.
◆
If you want to clean a drive that is being migrated from one operating system to another
(for instance, from UNIX to Macintosh).
Should you decide low-level formatting is necessary, keep in mind that it can take up to three hours or more (depending on the size of the drive). Avoid power interruptions and computer bus resets during the format operation or permanent damage to the drive could occur. In ad-
Appendix A: Connecting SCSI Drives
101
dition, leave the drive powered on for at least 30 minutes prior to formatting so that the drive has time to make any necessary thermal adjustments or recalibrations.
Partitioning Drives
Partitioning divides a physical drive into multiple, unique volumes, almost as if you were creating virtual hard drives. Partitioning is usually performed when the drive is high-level formatted (Macintosh) or initialized (Windows).
Mac OS allows drives larger than 4096 MB to be seen as whole volumes. Drives must be initialized with a disk utility that recognizes the 2 terabyte limit. Single Pro Tools audio files cannot exceed 2048 MB in size.
Avoiding File Fragmentation
For maximum recording and playback efficiency, data should be written to your hard drive in a contiguous fashion—minimizing the seek requirements to play back the data. Unfortunately, your computer can’t always store the sound files in this way and must write to disk wherever it can find space.
In multitrack recording, audio tracks are written in discrete files, spaced evenly across the disk.
While fragmentation of individual files may be zero, the tracks may be far enough apart that playback will still be very seek-intensive. Also, the remaining free space on the disk will be discontiguous, increasing the likelihood of file fragmentation on subsequent record passes.
Increased fragmentation increases the chance of disk errors, which can interfere with playback of audio, and result in performance errors.
On Windows, to avoid fragmentation, format drives with higher cluster sizes (such as
32K).
Windows XP allows drives formatted with the NTFS or FAT32 file systems to be seen as whole volumes. Single Pro Tools audio files cannot exceed 2048 MB in size.
Seek Times on Partitioned Drives
Seek times are actually faster on partitioned drives (assuming that reads and writes are performed on a single partition), since the heads only have to seek within the partition boundaries, rather than the whole capacity of the drive.
Smaller partitions perform faster than larger partitions, but this comes at the expense of contiguous storage space. When you partition a drive, you will need to find the compromise that best suits your performance and storage requirements.
Avoid distributing audio files within a session over different partitions on the same drive since this will adversely affect drive performance.
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Getting Started with HD
On Macintosh, if Norton Utilities is used, it must be Norton Utilities v4.0 or later to ensure compatibility with HFS+ drives.
Optimizing (Defragmenting) Drives
To prevent fragmentation, you can optimize your drive, which rearranges your files into a contiguous format. Most optimizing software lets you run a check on a drive to find out the percentage of fragmentation. If your drive shows moderate to heavy fragmentation, you should consider optimizing it.
If you use your system for intensive editing, or if you frequently delete audio or fade files from your hard drive, you may need to optimize your drives on a weekly basis, or even every few days, since it doesn’t take long for even a large hard drive to become fragmented.
Backing Up Data Before Optimizing
Since your files will be rewritten by the optimization process, always make a backup copy of the data on your hard drive before you optimize it. You should also use a hard drive utility to find and repair any problems before optimizing data or re-initializing your drives. If there is any damage to your hard drive's directories prior to optimizing, serious data loss may result.
Using Macintosh Drives on
Windows Systems
Pro Tools for Windows lets you record and play back sessions directly from a Macintosh-formatted (HFS or HFS+) drive connected to a Windows system. This functionality requires that all Macintosh session and audio files be stored on Macintosh-formatted drives.
To mount HFS or HFS+ drives on a Windows system, you must use the MacOpener
™
software utility by DataViz. An installer for the demo version of MacOpener is included as an installation option for Pro Tools.
For details on sharing sessions between
Macintosh and Windows systems, see the
Pro Tools Reference Guide.
Installing the MacOpener Utility
To Install MacOpener:
1
Quit Pro Tools if it is open.
2
Locate the macopener executable (.exe) file in the above location and double-click it to launch the installer.
3
Follow the on-screen instructions to install
MacOpener.
4
When installation is complete, restart your computer.
Enabling the MacOpener Driver
When you are finished installing MacOpener, the MacOpener driver must be enabled to mount HFS and HFS+ drives.
To enable the settings on the MacOpener Driver:
1
Choose Start > Programs > MacOpener >
MacOpener Driver Preferences.
2
Under Driver Settings, select Enable Mac-
Opener Driver.
3
Under Extension Mapping, select Do not add the PC extension to the Mac file name.
Mounting HFS Drives
If the MacOpener utility is installed and enabled, no additional steps are required to mount
HFS drives. They appear as normal system drives after you connect them and restart your computer.
Appendix A: Connecting SCSI Drives
103
Formatting and Maintaining HFS and HFS+ Drives
Although you can use MacOpener to format HFS and HFS+ drives from a Windows machine, this is not recommended for use with Pro Tools. We recommend that you connect the drives to a
Macintosh computer (if possible) and use the
ExpressPro-Tools (for Mac OS 9) or ExpressStripe
(for Mac OS X) software from ATTO, included on the Macintosh Pro Tools Installer CD-ROM.
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