Hard Drive Specifications

For Session^™ Software for Windows with Audiomedia III^™

March, 1996

EIDE Drives:

Types of EIDE drives supported include:

• EIDE

• Fast ATA

• Fast ATA 2

The EIDE drive must be installed internally, and connected to the embedded EIDE controller resident on the motherboard of the computer. EIDE controller cards are NOT supported.

Average seek time: 12msec or faster

Transfer Rates: - this is directly affected by PIO (Programmed Input/Output) mode

• Mode 3 allows a maximum burst rate of 11.1Mb/sec

• Mode 4 allows a maximum burst rate of 16.6Mb/sec

IMPORTANT: Your computer's BIOS must support PIO Mode 3 or 4. Please consult your computer motherboard manual or the manufacturer for more details.

Spindle speed: 5400 RPM or faster is recommended. The minimum speed is 3600 RPM, but seek times will be lower as a result.

Cache size: 128K or larger.

SCSI Drives:

Digidesign Session Software for Windows with Audiomedia III supports only single-ended SCSI drives and PCI bus SCSI controllers. SCSI controllers installed on the computer's ISA bus are NOT supported.

Recommended SCSI controller settings:

• Synchronous transfers enabled

• Throughput of 10Mb/sec

Average seek time: 10.0msec or faster

Sustained transfer rates:

• Read: 4560Kbytes/sec (4.6Mb/sec)

• Write: 4760Kbytes/sec (4.8Mb/sec)

• Read/Write: 3495Kbytes/sec (3.5Mb/sec)

Spindle speed: 7200 RPM is recommended. The minimum speed is 5400 RPM.

These specifications were qualified at Digidesign with the following system configuration:

• CPU/OS: Pentium 75Mhz; Award BIOS v4.50PG; Windows 3.1.

• Controller: Adaptec 2940 PCI SCSI controller; synchronous transfers enabled (max 10Mb/sec).

• Hard Drive: Avid Seagate ST15150N, firmware 3308; partitioned into two 2048mb volumes using FDISK.

• Test Tools/Suites: CoComp SCSI Toolset; Transfer block size-512 bytes; Test length-100,000 operations per pass, 10 passes per test.

The following drive configurations are NOT currently supported for Session Software for Windows:

• Wide SCSI

• Opticals

• Disk Arrays

• CDR and CDRW (CD Recorders)

• Removable Media (Jaz, Zip, Syquest, etc.)

Dedicated Servo vs. Embedded Servo

Dedicated Servo is a head positioning technique that requires a "dedicated" platter surface and head to position the read/write heads. Servo information is contained on the dedicated platter, which is tracked by the dedicated head. The remaining read/write heads are then slaved to the dedicated head. Dedicated servo drives require thermal calibration cycles to update head position at regular intervals, which can cause dropouts in the recorded audio or stuttering during playback. When purchasing a dedicated servo drive, we recommend getting a drive with A/V firmware installed. A/V will interrupt the thermal calibration cycle until the drive has completed a command.

Embedded Servo is a head positioning technique that intersperses servo information between the data tracks on all platter surfaces. The read/ write heads transmit the servo information to the drive's electronics, which in turn position the actuator arms so that the heads receive the maximum signal from the servo bursts. Maximum signal occurs only when the heads are directly over the center of the track. The read/write heads constantly receive tracking information, and therefore, are always aligning themselves. Embedded servo drives do not require thermal calibration cycles to update head position. The embedded servo technique can be found in most drives on the current market, and is highly recommended for use with Session.