Macintosh SCSI Hard Drives FAQ's

What are the 'Measurements of Hard Drive Speed' I need to consider for my needs?

Quick answer:

Seek time - is one of the most important measure for everyday tasks.
Burst Speed - High End Drives over 130MB/second Burst Rate explode most normal routines into almost real time, even on Vintage Macs.
RPM (Revolutions per Minute) - This is important, however High end 7200 RPM Hard drives with Seek times of under 7ms are comparable to or equal to a 10K drive.


Virtually all stock Macintosh scsi hard drives have a seektime of 13ms and higher.

All Beige Macintosh PowerPC Macintosh Computers including all 9xxx 8xxx 7xxx, and before are 13 ms or higher (except custom G3 Minitowers with 68 pin drives).

RPM is how many times a a platter spins (revolutions) per minute.
- The part that holds the music, pictures and other data in a scsi hard drive is a series of platters (looks like cds). These platters revolve like a cd player. As cd players can be 4x's 24x's or 52x's most stock Macintosh Hard drives are 4200 RPM to 5400 RPM.

Our 9gb IBM Ultrastar scsi hard drives are 4.9 ms and 10,000 RPM
18gb IBM Ultrastar hard drives are 6.5 ms seektime and 7200 RPM
50gb Seagate SCSI hard drives are 8.4 ms and 7200 RPM

There are three things to consider

• Maximum Data throughput
• Sustained Data throughput
• RPM (revolutions per minute) and Seektime

Sustained Data throughput is usually limited by the bus it runs from.
For instance, opening an application and any other normal activity require relatively little to be sent through the bus This includes any Microsoft Word document, Excel, PDF's, and most small-sized graphics and pictures.

OUR Hard Drives cause these documents to open instantaneously on most Macs , without increasing the RAM at all.

Thus the RPM, Seek time and Max Data Transfer are more important. The faster the Seek time and RPM the faster the application and above documents will open.

Seek time is how fast the hard drive can find the application you are opening.
A good comparison is how much faster the stock drive opens an application vs if the application was on a floppy is about how much faster a high end server drive is compared to the stock hard drive.

The 50 Pin bus of Most Pre G3 Powermacs such as the 7xxx 8xxx and 9xxx have 10MB/second bus speeds.

By Comparison, the ATA drives in the G3 Beige for instance, move data at less than 5MB/second and can only write one job at a time vs the SCSI which can perform multiple operations at once.

Our 9gb hard drive can run on SCSI PCI Cards on the 50 Pin bus, which usually transfers sustained data at 20MB/second

The 18gb hard drive runs at 20MB/second on a 68 pin UW or W bus (up to 40MB/sec as a two bus RAID, (where two hard drives work at the same time as one hard drive).
the 9gb hard drive runs at 40MB/second on a 68 pin UW bus (80MB/sec as a two bus RAID) and 160 (320MB/sec RAID) on an ultra 160 scsi controller card.

Does the 9gb/18gb/50gb hard drives work with the 7xxx Series?
Yes, it works in every 7xxx model including all speeds of the 7100 7200 7300 7500 7600 Power PC Macs

The Drive works with all 7xxx Models. The 18 and 50gb drive is 1.6 inches tall and must fit in the lower middle bay.

The 8xxx
Yes, it works in every 8xxx model including all speeds of the 8100 8200 8500 8600

The 9xxx Series Yes, it works in every 9xxx model including all speeds of the 9500, 9600

Some early models of the 9500 need termination at the end of the scsi bus. This is done with a terminated drive (such as the stock hard drive) or a 50 pin active terminator at the end of the ribbon.

If multiple unterminated hard drives are on the bus a terminated drive or terminator needs to be at the end of the scsi chain. All stock hard drives are teminated.

Special Notes

The 7600 will need a 2-3 inch or longer power cable extender only if two hard drives are installed at the same time.

7300 7500 7600 compatibility with G3 Upgrade Cards
We have found the drive to work with the 7300 7500 and 7600 with all G3 and G4 CPU Upgrades tested so far, including Sonnet, XLR8, and NewerTech.

See a Pictorial Manual for the 7300 here

Blue and White (B/W) G3 Towers

This drive will work with the 68 pin scsi pci controller card that is installed in many B/W G3's and some Beige G3 minitowers.

To determine if you have a scsi pci controller card, do the following:
1. Check your owners information or

2. With the computer turned off and unplugged, gently pull the circle on the side of the G3 B/W computer. This will open the computer.

Look at the big flat green motherboard that has everything connected to it.
Look towards the back of the computer. There are "slots" called pci slots that are thin and long. If you see a card standing in one, and facing outside the back of the computer where something outside can be plugged in, that may be a scsi card!

Look on top of that card for two places where one can plug something in. If there are two places, one longer 2.75 inches and one that is 1.75 inches, the smaller one is the 68 pin connector (picture represents a scsi pci card with two connectors.) Your card may have a different design, however if it has the two connectors on the top as this one does, it is a scsi card. In this picture there is a 68 pin ribbon already connected to the card.

3. Check Apple Menu --> Apple System Profiler --> Devices and Volumes
for a pci scsi card that ends in UW or U2W or U2B. This may not cover every card that works, however it covers the majority of them. You must click the triangle to read the detailed information.

Blue & White G3 Tower Installation notes

Mac OS compatiblity: OS 8, 9 and OS X
All pre-installed SCSI cards from Apple can use this drive to boot OS 8,9 and OS X.
Ask for more help with "pre-formatted 'blessed' hard drives for booting OS X".

Concerning Installation
The towers can use this drive when installed on the bottom of the unit, However,
bolting the drive to the Computer is not possible (usually) and so care must be taken with the computer.

Additional care

• Don't move the computer while it is on
• Care is needed while moving and shipping the computer (temporarily uninstalling the drive is the recommendation).

Some Blue and White G3 Towers have a metal frame on the top of the tower
to hold another drive. This is for a 1 inch drive, however installing a 1.5 inch frame to bolt the drive may be possible.
We have had comments from customers both that have kept the drive and are happy,
and others who are not comfortable with the modifications necessary to have the drive installed.

G3 Beige Desktop
(may need a SCSI ribbon Only $7.99 including shipping
Drive is fully compatible with the machine, however it must fit where stock drive is, or lower middle bay. (You can place the stock drive in the open bay).

Some G3 Beige Desktops use a SCSI Zip Drive and not IDE. These machines can use the 18gb drive with the Zip drive installed with a long scsi ribbon to reach both devices (available). See below how to do a quick check on your G3 Beige desktop.

How to check G3 Beige Desktop compatibility:
1. Choose Apple System Profiler from the Apple Menu. 2. Click on Volumes and Devices. If it lists the Zip as IDE, EIDE, or ATAPI there is no need for a long scsi ribbon, although you may need one. 18" ribbon is optimal.

If it is a Zip SCSI you will need a longer ribbon to reach both to where the stock drive is (bottom left) and to the zip drive, or un attach the zip.

We will gladly refund money if you are unable to install, however in order to save time, please ask about your model if not sure.

I have a Beige G3 mini-tower that has its original 2 drives running off a pci scsi card. There is an empty drive bay. Can I add an 18GB drive to my system or would I have to replace one of the 4GB drives?

the drive is 1.62 inches high and standard 3.5" width.
As long as it can fit or if you can move a drive, it shouldn't be a problem.

The drives seem to work best on 68 pins.
68 pin 18gb drive for 20MB/sec and 132MB /sec burst speed $44.95.

If you need a 68 pin card for a second bus, we have that as well, a 3940uw including a 68 pin, and a 50 pin cable (Domex is the brand). Made especially for G3's including the minitower. and new in box. 19.95 plus $5.95 shipping. Can run up to 15 drives including a 68 pin external bus, (only 2 of three busses can be used at the same time).

TroubleShooting

My Hard Drive Won't Mount! What do I do?

1. Apple suggests "when a hard drive doesn't mount, use Drive Setup and update the driver, on restart it will mount..
2. Contact us here

Apple System Profiler doesn't show the correct information with System 8.x

Apple System Profiler from OS 9 has been updated to indicate the correct information. Click here to download a copy. *owned solely by Apple Computer and for informational use only.

Can this drive run OS X?
Yes, the drive is great for OS X because of its speed, dependability, and its size.
You can quickly partition the drive for having OS 9 on its own partition (recomended) with Apple Drive Setup in your Utilities Folder.

Partitioning for OS X
The ideal strategy for installing Mac OS X is to have three separate partitions: one for Mac OS X, one for Mac OS 9.1, and one for Classic. These partitions can be on the same disk or on separate disks--it does not matter.
If you are installing onto an ATA drive, Apple states to install onto a partition that is entirely within the first 8 GB of the drive. The Mac OS X Installer enforces this limit, so if you are unable to select your desired partition, that may be the reason.

Two partitions, one for Classic and one for OS X is the next best choice. One partition will work.

Other experiences with OS X and the 9500

If you use the Sonnet 800 card you need both Other World Computing L2 Cache Config to enable the L2 cache and Powerlogix Cache Control 2.1 to enable the L3 cache.

Can I run OS X on Pre-G3 Machines?
While Apple has limited its support for Mac OS X to those machines that originally came with a G3 or G4 processor, it is possible to install Mac OS X on some earlier machines. The unsupported machines that work now are the 7300, 7500, 7600, 8500, 8600, 9500 and 9600, as well many clones that were based on one of these systems. Installation requires only three extra clicks! As of July 7th, G3 upgrade card required. Check current requirements.

Q: Hello and thanks for your time. I have a PowerCenter 150 desktop whose 1GB
hard drive is almost full. I would like to add another internal drive, about
20 to 40GB. Do I need to add a PCI card too? What's the difference between
68 pin and 50 pin drives? Do I need separate "ribbon cable" and/or power
connection? Can you customize a package for me?

A: For OS 8.6 or 9.1 this 68 pin package runs at 131MB/sec Burst and 40MB/sec sustained for large data transfer. Includes everything you need for 68 pin speed (4'xs the rate of 50 pin speed). More info Here.

100% money back if not fully satisfied.
Let me know if you have further questions.