View Full Version : G4 Sawtooth and SCSI

01-29-2001, 09:35 PM
> Gentlemen:
> I gave a friend of mine a 29160N Adaptec SCSI card for his brand new G4
> Sawtooth. I couldn't imagine why the machine wouldn't boot from a SCSI
> drive until I saw a reference to the problem on your site and an indication
> that Initio had a fix in place for the Miles U2W for the same problem. Is
> such a fix contemplated or available for the Adaptec card? I could find no
> information on their site.
> The same friend of mine has a 6400 Performa and I told him he could
> probably take the drive out of that and put it in the G4 as a backup drive.
> Is that so or not? Where is the straight dope on IDE, EIDE, and ATA? Are
> they interchangeable? I thought that ATA and IDE were the same thing...
> Thanks. Sorry to be so dense...Tony Austin

01-29-2001, 11:39 PM
I did not know of any SCSI boot issues with the 29160 or any other scsi card. The 2906 (or whatever) isnt bootable, but then its a seriously cheap card. The only other issue would be if he is trying to boot from a RAID 0 setup. Single volumes and even RAID 1 should work fine - assuming there is a valid system folder on it.

Any IDE/ATA drive from a 6400 will be old, small and slow. I wouldnt use it with a new G4. In fact I took a 6G IDE/ATA drive out of a B&W G3 and put it in a C600 (6400 clone) it works pretty good. Not sure about putting slower IDE/ATA drives on a faster bus.... I do not think it drops the bus down - like SCSI.
IDE standards -
Beige G3s were the first top end mac to have IDE/ATA as the main drive. They are ATA/3 - or 16MB/s. IDE can only support 2 drives per channel, but many Mac models can only support one per channel and/or are very picky about the second drive.
B&W G3s were the first Macs to have NO SCSI. They only have ATA/IDE drives and run an ATA/33 (33MB/s) for the HDs and I think its still a ATA/3 for the CD/DVD/ZIP etc...
YIKES - same as B&W but has G4.
Sawtooth - Graphite G4 runs ATA/66 for the main HD bus.

The IDE/ATA PCI cards are basically fake SCSI cards - so you have to reformat to move those drives form a stock mobo bus to the pci card and so forth.

Macs support just about every IDE/ATA drive. They are fast and cheap single drives. RAID isnt so good on them and you can only run them internally.

SCSI drives are generally the same speed when looking at single drives, but are much, much more flexible with RAID arrays, low level formats and externals. You can also get 15 drives per WIDE card - try that with an IDE bus. SCSI also last longer.

01-30-2001, 02:19 PM
I am not aware of any boot issues with the 29160 from Adaptec in the new machines....I know they are not compatible with vintage machines, but that isn't what we're discussing here. Check the Adaptec website for firmware updates, and make certain that you have your drive correctly configured as far as termination and addressing are concerned.

Pen18 is correct when he states that you cannot boot off a RAID 0 or RAID 1 volume on New World Macs. (You can, but it is not supported, nor is it easy). Make sure that your volume is formatted as a single HFS+ volume.

your pal may be able to pull his IDE drive from his 6500 and put it in the Sawtooth, but he will need to configure it as a slave or master drive, based on what else is on the IDE bus. I would also update disk drivers immediately, to ensure compatibility.