Studio Array Q&A December 12, 1995Return to the Radius Technical Support Q&A CatalogComments firstname.lastname@example.org
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December 12, 1995
Q: Which Macintosh platforms are supported by the Studio Array?
A: Studio Array is designed for the Power Macintosh 8100, 8150, 9150 and the Quadra 840av. The Studio Array product will work in other full sized NuBus based Macintoshes, however due to NuBus limitations, the Array performs under specification. The Studio Array was primarily designed for use with Video Vision Studio. However, it will work with SuperMac Digital Film, but is not recommended for use with the Spigot PowerAV product.
The Studio Array JackHammer Card is a NuBus card and does not work in the PCI based PowerMacs, such as the 9500, 8500, 7500, and 7200 series of Macintoshs.
Q: I am getting poor data rate performance from my Studio Array. What's wrong?
A: There could be several issues.
First, you should check to make sure that HammerTime 1.1 extension and the JackHammer 3.2 control panel are loaded. If these are loaded, check if the drives are striped. The easiest way to check this is to copy a file (of about 50k in size) from your internal drive to a partition on the array. If both red lights on the array flash, then the drive is striped. If only one red light flashes, then the Array is not striped and will give poor performance. If this is the case, you must follow the restriping instructions in your RaidToolkit manual.
Second, SCSI-2 cables are somewhat sensitive to movement. You should check the connections of your cables between the JackHammer card and the Array. You should also check the terminator and the junction cable that runs between SCSI drive A and SCSI drive B. If any of these pins are bent or missing, you need to obtain replacement cables by dialing Radius at 800-977-7060 and ordering part number 590-0219-01.
Finally, you should not attach any other SCSI-2 devices to the JackHammer card other than additional 4GB Studio Array Modules (model #0495).
Q: I have a Macintosh 840av and the "Maintain Data Rate" feature reports a data rate lower than what the drive is supposed to do. When I manually set the Data Rate higher, it works. What am I doing wrong?
A: On an 840av, the data rate estimator may return 4.7MB/sec, which is well under the rated performance specifications. This is typically due either to a JackHammer control panel default called "Lock NuBus Transactions," or because the HammerTime INIT is not installed. To fix the "Lock NuBus Transactions" issue, open the JackHammer control panel, click on "Slots", then click "Advanced Options", then click "continue", and then uncheck "Lock NuBus Transactions." After closing all dialogs and restarting your Macintosh, the data rate estimator will return more accurate numbers. This feature is not supported on the Power Macintosh.
Q: My array will not mount. What's wrong?
A: Failure to mount the arrays (the ability to see them on the desktop) is generally attributed to two things: Pushed or bent pins on the connectors (by far the most common), or conflicting SCSI ID's with other modules on the bus. A visual inspection of the cable and terminator connectors will usually, but not always, reveal bent or damaged pins. This is particularly frequent with systems that are disconnected and reconnected frequently, such as trade show units.
The connector needs to be secure at both ends. Usually, this can be determined by listening for the audible click from each side.
When checking for conflicting SCSI ID's, look at the back of the Studio Array. There are two selector switches labeled "A" and B" with a number between 1 and 6 in a clear window. These numbers are the SCSI ID's for the Studio Array. "A" and "B" should have unique values. For example, the Array should ship with switch "A" set to ID=5 and switch "B" set to ID=6. If the ID's are the same, use a pen to push in the selector switch to change the number. The ID's should be set in consecutive order. For example, if switch "A" is set for ID =3, Switch "B" should be set for ID= 4.
Q: How many minutes of video can be stored on a 4GB Studio Array?
A: This is dependent on the data rate you chose. Higher data rates consume disk space faster, and therefore, limit your recording time. The amount of video that can be recorded before a volume becomes full is directly proportionally to the data rate of the video that is recorded. For example, if you record at 2 megabytes per second, a 2 gigabyte volume will be filled after 1000 seconds, or 16 minutes and 40 seconds. Recording to the Studio Array at the Maximum supported data rate of 6.5MB/second will limit the recording time to just over five minutes per 2 GB volume.
Q: Which defragmentation utility should I use with Studio Array?
A: We recommend ALsoft's Disk Express II (which is shipped along with Video Vision Studio and the Video Vision Studio Pro Pak). We have received unconfirmed reports that certain utilities like Norton's Speed Disk have caused problems with the Studio Array.
Q: I heard that some Disk Arrays have problems with QuickTime 2.0. Is the Studio Array QuickTime 2.0 compatible?
A: Yes. The Studio Array is QuickTime 2.0 compliant. You must have the correct StudioArrayToolkit Software. The current revision is 1.6 and contains the following items for QuickTime 2.0 compatibility:
Studio Array Tool kit 1.1
Q: I am running Macintosh System 7.5 which allows me to mount my Studio Array as a 4GB Volume, however when I capture video using my QuickTime application, it tells me I am out of disk space at 2GB? What's wrong?
A: Although System 7.5 allows you to mount a 4GB partition, the size of a single file is still limited to 2GB. It is still recomended to leave the Studio Array formatted into two, 2GB Striped Partitions. This has shown to matain more reliable performance.
Q: I just defragmented my Studio Array and now every time I capture a QuickTime movie, I get error message that states "Unable to open video data track on movie 'untitled-1.'". What's wrong?
A: You are most likely running QuickTime 2.0. Occasionally, on a completely defragmented drive, QuickTime 2.0 will have trouble writing the proper data track. The solution is to copy a file (50k or so) from your internal drive to the Studio Array and then capture your movie. This will allow QuickTime to correctly write the data file.
Q: What drive mechanisms are used in the Studio Array?
A: The Studio Array uses two Seagate ST12550WD Barracuda II Wide 2.1GB mechanisms. These drives are rated at a Spindle Speed of 7200r.p.m and Average Seek Time of 4.25ms. Power Consumption is 30 watts.