[Eric E.]

I have a Digital Audio 466 that currently has 3 internal hard drives (two Maxtor 80 gigs and the stock IBM 30 gigs) and the stock Sony CD-RW drive. Can the power supply handle a total of 4 or 5 internal hard drives along with the CD-RW drive? My monitor is a CRT, so it's not getting power from the video card.

Eric

[bowwowman]

Yes it will...

That machine was designed to power a total of 6 drive units, 4 HD's, a CDRW, and a Zip drive. If you dont have the Zip, then you should have plenty of power for at least 2 more drives.

Assumming, of course, that the drives you install are not some super-duper-juice hogs that require a nuclear reactor to run

[Eric E.]

bowwowman... Thanks for the reply. There's no Zip drive in my machine, but I'm planning of putting the stock IBM hard drive in the space below the CD-RW and add two more hard drives in the space below it, for a total of 5 hard drives. I'm a bit stingy to buy external drives. I hope that heat will not be an issue.

Eric

[tooki]

Whooa, bowwowman, he said Digital Audio G4, not Mirrored Drive Doors! All G4s before the MDD models are designed for 2 hard drives (IDE or SCSI). Because of each interface's cabling requirements, and the fact that SCSI drives are sometimes bigger, there are 4 hard drive bays, but only 2 are supposed to be populated.

The Digital Audio G4 is designed to handle 4 drives in total, namely, one optical, one zip, and two hard drives. You can't really use the zip bay for a hard drive because it lacks the necessary cooling (although if you chose a drive that runs cool, you'll be fine anyway), but the zip interface will hobble any recent hard drive, since it won't run at even ATA/33 speed.

Your power supply can probably handle it (since it is designed to allow 2 SCSI drives, which can easily eat twice as much power as an average IDE drive), but cooling can be an issue.

3 hard drives I wouldn't worry about, but 4 or 5 is really pushing it, and may blow a fuse in your power supply (I am not sure whether the fuses are self-resetting or not).

tooki

[Slaveway]

I currently have four drives in my Dual800 and I have run it with six using one of those PCI cards.
Had to buy a splitter for the power supply but I never noticed any problems with the machine.

[riverfreak]

I have a blue and white G3 that has six drives in it.

Three along the bottom tray, two stacked in a rev2 stacking tray and placed ontop of the CD-ROM, and one in the zip slot.

In order to do this, I had to get Y power adaptors and an additional PCI IDE card that has two buses (as well as some creative cabling), but the system has been running like that day in and day out for over two years as a server.

No problems.

[GoGoReggieXPowars]

G4/400 Sawtooth, formerly populated with the following:
stock 10G, added 7200RPM 60G, 5400 60G, DVD/CDRW combo and a 9G Ultra SCSI drive. So 4HDs. Then I bought a 120G 7200 RPM drive to replace the 2 60G drives. No problems so far.

The 5400 60G drive was in the ZIP slot.

[scottiB]

G4 800x2: factory installed 80 GB+SuperDrive+Zip250; 60GB slaved off factory 80GB; 2x120 WD Jumbo RAIDed with a SIIG card mounted side by side on the chassis floor (where the SCSIs would be mounted, I believe). No problems--yet.

[Cipher13]

G4/400 Sawtooth.

Stock 237 watt PSU.

DVD-ROM, CD-RW (SCSI), 60 gig Barracuda at 7200, 10 gig Quantum at 7200, 4 gig Caviar at 5200, plus the SCSI card.

No hiccups at all.

[Jansar]

No problems here, although I use a Mirrored Drive Door Mac.

2 x 120 GB drives (in the ATA 100 spaces)
plus Superdrive and Combo Drive

Two more HD spaces remain, but I believe that only ATA 66 drives can fit there.

[bobvila]

2 x 120 GB drives (in the ATA 100 spaces)

Two more HD spaces remain, but I believe that only ATA 66 drives can fit there.

Wouldn't a faster system speed result from utilizing both buses instead of connecting two harddrives to the same bus? Although the other bus is ATA66, I think connecting one drive to the ATA66 and one to the ATA100 would be faster than two harddrives on the ATA100.

[bowwowman]

tooki,

I hate to say it, but it appears that you have been outnumbered

I too have a B&W (now a G4/650!) with 4 EIDE HD's, plus CDRW & Zip in it. I use a Tempo 100 controller for the hd's...

My friend across town has his D/A G4 with the exact same setup

SCSI ? over my dead body!
Cabling? standard 18" 2-connector ribbon (came with the ATA card)
Size ? Last time I looked, all EDIE desktop hd's where virtually the same physical size

And why would anyone design a comnputer case with the capacity & space to hold 4 HD's and then tell you that you could really only put 2 in there ???

well duh

[ReggieX]

Originally posted by bowwowman:
SCSI ? over my dead body!

Truly asynchronus disk access makes Photoshop happy

[s_surfer]

Originally posted by tooki:


The Digital Audio G4 is designed to handle 4 drives in total, namely, one optical, one zip, and two hard drives. You can't really use the zip bay for a hard drive because it lacks the necessary cooling (although if you chose a drive that runs cool, you'll be fine anyway), but the zip interface will hobble any recent hard drive, since it won't run at even ATA/33 speed.

Your power supply can probably handle it (since it is designed to allow 2 SCSI drives, which can easily eat twice as much power as an average IDE drive), but cooling can be an issue

tooki

Does that mean I can install an ATA drive where the zip drive would go and attach it to the zip ATAPI interface? I already have 2 ATA drives installed on my PM G4 AGP (Sawtooth) but I want to install a higher capacity drive and need a way to temporarily attach it so I can copy the data off the current drive(s).

I don't care if it is slow and it won't be in long so I doubt heat will be an issue. I just need to know if okay to attach an ATA drive to the ATAPI interface and power connector. If it works which settings are required on the drive (e.g. Master? Slave", etc.)

...Steve

[tooki]

s_surfer: yes, you can use the zip connector for that, i've done it before. Just jumper the drive as slave.

Originally posted by bowwowman:
tooki,

I hate to say it, but it appears that you have been outnumbered

I also said that it is pushing it, not that it will never work.

I have seen (as in, witnessed) Macs have enough drives that it didn't have enough power to spin them all up.

It's also true that as drive technology evolves, they use less power. Also, SCSI drives typically use a lot more power.

tooki

[Hash]

Hey guys, i have BW G3 now with G4 650 mhz and 3 hard drives, 2 are on PCI IDE bus.

My question: does any of you have troubles with OS X? On which drive you put it? Mine is on drive connected to IDE PCi card and on cold boot I get 2-3 kernel panics - warm boots are fine though (go figure). I also have USB2 PCI card. Does any of you have it in addition to 3-4 drives?

Second question: i am thinking about replacing power supply to 300 W and adding a 4th internal drive..Your recommendations?

[Eric E.]

Thank you very much to all who replied. I'll proceed with my plans as soon as my budget will allow me to purchase 2 more (to add to the 3 that I already have) hard drives for my Digital Audio 466.

Eric

[Simon]

Originally posted by bobvila:
Wouldn't a faster system speed result from utilizing both buses instead of connecting two harddrives to the same bus? Although the other bus is ATA66, I think connecting one drive to the ATA66 and one to the ATA100 would be faster than two harddrives on the ATA100.

Some time ago I asked a similar question in another thread and the answer I got (sorry for the missing citation, but I can't remember who gave it to me opr in what thread)sounds pretty reasonable. Here goes:

If you put both on the ATA66 they have 33MB/s bandwidth per disk. Most credible ATA disk benchmarks we get to see show that the sustained data rates for <= 7200RPM ATA disks don't go much higher. Maybe in a burst mode, but not sustained and most of all not when the disk is filling up. So basically it probably doesn't matter if you put one on the ATA66 and the other on the ATA100 or both on the ATA100. In my new MDD PowerMac I have tried both (with two 7200 RPM disks). I had one on the 100 and one on the 66 as well as both on the 100 and both on the 66. I didn't feel a difference and I wasn't able to measure a significant difference for sustained performance.

[[email protected]]

i've got 5 in the g4 right now.

Four 80GB mambos on a ATA 133 RAID card, and one 45GB on the internal ATA 66 bus.

runs just fine.

[tooki]

Originally posted by Hash:
Second question: i am thinking about replacing power supply to 300 W and adding a 4th internal drive..Your recommendations?

Don't even bother. Apple didn't make a bigger power supply for that model, and since it's a special design, you can't just replace it.

Originally posted by Simon:
If you put both on the ATA66 they have 33MB/s bandwidth per disk.

Wrong. IDE does not "share" like SCSI. (And even SCSI doesn't share its throughput that way.) IDE actually does not allow both devices on one bus to communicate at the same time, they are required to take turns. So if you put two ATA/66 drives on an ATA/66 or faster bus, then the drives will communicate at 66MB/sec, but only one at a time. So copying from one drive to the other drive on the same bus will result in roughly 33MB/sec, but that's not really a number applicable to any other situation.

tooki

[Simon]

Originally posted by tooki:
Wrong. IDE does not "share" like SCSI. (And even SCSI doesn't share its throughput that way.) IDE actually does not allow both devices on one bus to communicate at the same time, they are required to take turns. So if you put two ATA/66 drives on an ATA/66 or faster bus, then the drives will communicate at 66MB/sec, but only one at a time. So copying from one drive to the other drive on the same bus will result in roughly 33MB/sec, but that's not really a number applicable to any other situation.

Correct, but you're overshooting. I wasn't trying to imply that the disks share the channel like on SCSI. It was simply an estimate for what kind of bandwidth disks would need to have to make the bus the bottleneck. If you take your ATA66 bus and two drives (constantly trying to read or write) they won't share, but if you integrate each of their bandwidth consumptions over larger times you will indeed get about 33MB/s per disk. That was just an estimate, not a hard number.

[tooki]

You'd get 33 only in a theoretical situation of 50/50 FULL-TIME access, assuming both read/write processes have the same priority in the OS. Since hard drives aren't (in a typical desktop environment) being accessed anywhere near 100% of the time, your average individual throughput could be much higher, drive speed permitting.

If each drive is being accessed, say, 5% of the time (a guesstimate for, say, office work), then the chances of them both being accessed at the same time is 0.05x0.05=0.0025%. That sliver of time is the only time when a given drive couldn't work at full speed. (This is the same reason why two people sharing an internet connection don't really step on each others' toes much.)

Even things like video don't tax the drive that much... it may be in use full-time from a user perspective, but a drive reading DV video is reading 3.6MBps, or about 10% of the maximum sustained throughput of a modern drive.

The thing about IDE is that one drive can't talk until the other one has completely finished a transaction -- even if the busy drive isn't actually communicating at the moment. But again, that's still doesn't cause problems until the load on the drive becomes quite high indeed. That's why servers, like the Xserve, put each IDE drive on a separate controller, while desktops don't bother.

tooki

[Simon]

Sorry Tooki, but I don't understand, WTH are you trying to say?

He wanted to know if he should put them on different channels. The point is that it doesn't matter since these drives will not be saturating anything on his box over longer periods of time. So are you trying to back this idea up or are you trying to get him to put the drives on different channels.

If really wanted I could post numbers from the tests on my new dual G4 that show 7200RPM ATA drives don't get faster (by putting them on the ATA100 and ATA66 channels seperately) for sustained read or write performance.

[Hash]

Sorry for being unclear.

I intend to put in BW an ATX power supply AND I already bought it. Its 350 W power supply in a generic box and extremely lucky that it has all visible similarities with stock BW supply such as size, service power outlet for monitor (quite rare thing on cheap ATX PS units), 110-230 V input, and even location of bolt holes same to stock Apple power supply. I ll try tomorrow to put the babe in; i dont have now the required tool (size 10 or whatever).

[CIA]

I have a Dual 800 Quicksilver with the following inside:
Superdrive
Zip 250
2x 120GB 7200rpm Western Digital Special Edition drives hooked up to a SIIG RAID card (they are Striped together, each drive on it's own bus)
1 normal Western Digital 120GB 7200rpm drive on an Acard 133 PCI card
1, 60GB Maxtor 5400 also hooked to the Acard PCI card
The Stock 40GB that came with the machine on the built in ATA 66 bus.
The GeForce3 Card has a fan on it, but it does not power my moniter (non-ADC moniter hooked to it)
Also I have added an aftermarket PCI Slot fan, and another old ATI VR128 in the last PCI slot for a 2nd moniter.

I had to buy some "Y" power splitters, besides that she runs fine!
Just be aware that if you put a drive above the superdrive, it will get REALLY hot, next to the powersupply and all.

[Hash]

Well, I am reporting here results of the surgery

I put a generic ATX power supply with 350 W instead of stock 200W.

I have 3 hard drives, all 7200 and very fast combo drive, plus USB2 card, Radeon, PCI IDE card 66 mhz,
and an additional fan on G4 CPU (on the stock heatsink).


Most difficult part was removing the old power supply unit cause you need quite rare 2.5mm Allen screwdriver.

You also need an ATX power extension cable AND you must CUT wire #18 (white).

Then i put a new PC PSU inside the case and here are my observations.

1. Its really silent PSU unit, at least same as old stock one

2. I get less kernel panics in OS X ( i think USB-connected, since i had a lot of things on USB bus)

3. mac seems to be more stable, however its difficult to benchmark

4. I am ready for installation of 4th and 5th hard drives if necessary