[G4] ATA drives and buses in G4 Dual MDD

[Philip J Robar]

On Nov 9, 2005, at 11:58 PM, Aaron wrote:

> I've recently acquired a G4 Dual 867 MHz MDD that came with only  
> the original I (I think) drives. The HD has the following  
> description (excerpted from System Profiler):
>
>   Capacity:	57.27 GB
>   Model:	IBM-IC35L060AVVA07-0
>   Revision:	VA3BA52A
>
> The optical disk is the misnamed "SuperDrive" -- misnamed because  
> it should be called the "Super-Slow Drive". (It's presently out of  
> the computer while I'm working on adding another, faster drive, so  
> I can't look it up on System Profiler.)
>
> Anyway, I've added two Maxtor ATA133 drives (120 and 80 decimal MB)  
> and am about to add a Lite-On CD/DVD read-and-write everything  
> drive that reads and writes CD's at 48x (7200KB/sec) and DVD's at  
> 16x (21600KB/sec).
>
> I know that the machine had 3 ATA buses: ATA33, ATA66 and ATA100,  
> each of which can handle two drives, but will, presumably, slow  
> down if both drives are being accessed at once. I also have a  
> Sonnet Tempo ATA133 card that I can use if it would make a  
> substantial difference in speed.

Your machine has two ATA interfaces: ATA66 and ATA100. Get a copy of  
MacTracker to learn more.

Unless you've got something better to do with it you might as well  
use the Sonnet. That way you can put each drive on it's own channel.


> My general question is:
>
> What speed ATA bus (and what combination of devices and buses) will  
> get the maximum, or nearly maximum, actual transfer rate out of the  
> various drives?

Put the drives you use the most on the faster interface unless you  
tend to use them at the same time as only one drive on a interface  
can be accessed at a time.


> Specific questions include:
>
> What is the ATA speed of the IBM drive described above?

I could tell you, but it's better to teach a man to fish ... In other  
words Google is your friend.


> What speed of ATA bus is necessary to run the Lite-On drive at full  
> speed?

The ATA 66. ATA 33 would be good enough though.


> Will an ATA133 drive run faster on an ATA133 bus from an ATA133  
> card than from a built-in ATA100 bus?

Unlikely, and even if the difference is measureable you won't notice  
the difference.


Phil
--
"America is at that awkward stage. It's too late to work within the  
system, but too early to shoot the bastards." -- Claire Wolfe, 101  
Things to Do 'Til the Revolution