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Appleman · May 4, 2003, 05:29 AM

Having bought a 200 GB hard disk, my iMac 400 DV/SE slot loading only sees 137 GB, and currently now only 128.

According to this site at Western Digital first of all the OS should support it. Well I think that shouldn't be the problem.

Is it save to say I have to change the drive for a 120 GB, or is there a way to get by this barrier by using another program than Apple's Disk Utility to partition the drive or is it a limitation for this iMac?

Any ideas are welcome, would love to leave the disk inside...

JLL · May 4, 2003, 06:23 AM

It's a limitation of your IDE controller.

Appleman · May 4, 2003, 06:24 AM

Originally posted by JLL:
It's a limitation of your IDE controller.

I was afraid of it. This cannot be tweaked or altered?

Thanks.

chabig · May 4, 2003, 06:56 AM

Not only does the OS have to support the drive, the BootROM has to support it.

According to this Knowledge Base article, your computer does not support drives larger than 137GB (decimal bytes), which is the same as 128GB (binary bytes).

Your best bet might be to replace the drive with one that is fully supported, and put the 200GB drive into an external case.

Appleman · May 4, 2003, 07:03 AM

Originally posted by chabig:
Not only does the OS have to support the drive, the BootROM has to support it.

According to this Knowledge Base article, your computer does not support drives larger than 137GB (decimal bytes), which is the same as 128GB (binary bytes).

Your best bet might be to replace the drive with one that is fully supported, and put the 200GB drive into an external case.

Thanks for the link. OK, have to bring the drive back then.

Nebagakid · May 4, 2003, 07:58 AM

Originally posted by JLL:
It's a limitation of your IDE controller.

Said in an old British man's voice, some teeth are mising:
The only limitation, is your imagination

yeah, i mean, the Xserve products blast forth with 180Gigger's..

The_Equivocator · May 4, 2003, 10:46 AM

Just a shot in the dark... but what if you partition it using a different computer into two 100GB drives?

voodoo · May 4, 2003, 11:21 AM

Zat might vork Herr Doktor!

chabig · May 4, 2003, 11:28 AM

Partitioning it into two is a good idea, and worth a try. But I believe that technique is a workaround for operating system limitations. In this case, it's a limitation of the hard drive controller, so I suspect it won't work. Still, don't take my word for it--try it if you can.

piracy · May 4, 2003, 11:32 AM

Originally posted by The_Equivocator:
Just a shot in the dark... but what if you partition it using a different computer into two 100GB drives?

This won't work.

One "workaround" would be to get a FireWire enclosure for the disk and use it exclusively via FireWire. (Make sure the chipset in the enclosure supports 48-bit addressing, which is required to support "Very Large Disks", or disks larger than 137GB).

Or get a smaller drive.

chabig · 11:38 AM

Using it exclusively as an external firewire drive is a good idea. You can put the old drive back in. But if you want a large internal drive, you're limited to 128GB.

GENERAL_SMILEY · May 4, 2003, 11:41 AM

you coulld buy a RAID card, this will work - even with only one drive on some models - don't know if it'll fit in such a small computer though.

DaedalusDX · May 4, 2003, 12:39 PM

Originally posted by GENERAL_SMILEY:
you coulld buy a RAID card, this will work - even with only one drive on some models - don't know if it'll fit in such a small computer though.

The DV/SE iMac has no expansion to speak of, so that's not really an option...

No... Appleman, your only options are to return the drive, or get a firewire case that supports big drives. Once you do, that drive will be wicked fast... Western Digital 200 "Drivezilla" ?

Millennium · May 4, 2003, 04:40 PM

Allow me to interject that FireWire drive enclosures are teh b0mx0r. Seriously; you can usually get an internal drive and an enclosure for less than you'd pay for an external, and then it doesn't even take up any drive bays. Plus, it's nice and fast to boot.

It would be nice if someone would finally come out with a true-FireWire drive (current FireWire external drives are just ATA chips with a bridge). Now that would seriously rock.

Appleman · May 4, 2003, 10:04 PM

Originally posted by DaedalusDX:
The DV/SE iMac has no expansion to speak of, so that's not really an option...

No... Appleman, your only options are to return the drive, or get a firewire case that supports big drives. Once you do, that drive will be wicked fast... Western Digital 200 "Drivezilla" ?

This baby I have to bring back and change for a 120 GB...

road2osx · May 5, 2003, 03:32 AM

It has nothing to do with your IDE controller. It's merely a limitation of software and firmware, which means MacOS and BootRoom in Mac.

Drives larger than 128GB uses an extended LBA mode to access sectors. The extended command set includes: Read PIO Ext, Write PIO Ext, Read Multiple Ext, Write Multiple Ext, Read DMA Ext and Write DMA Ext. Which differs from ordinary PIO/DMA command set in only one aspect: LBA register usage. In all HD supports extended LBA, the LBA registers (LBA HIGH, LBA MID, LBA LOW) are implemented as a 16 bits FIFO. On every LBA reigster writing operation the contents in the first 8 bits (MSB) will be swapped into the second 8 bits (LSB). A total 3 16 bits register can support drives up to 128 PB, which maximum 65536 sectors per command.

There is, on the other hand, no physical (electronical) difference between them. That's why most hardware should be able to support drives larger than 128GB by firmware updating. I can actually accessing a 200GB drive by a single 8051 chip.

So partitioning the disk into two won't work as well. It's a problem of ATA command set implementation.

Appleman · May 5, 2003, 03:48 AM

Originally posted by road2osx:
It has nothing to do with your IDE controller. It's merely a limitation of software and firmware, which means MacOS and BootRoom in Mac.

Drives larger than 128GB uses an extended LBA mode to access sectors. The extended command set includes: Read PIO Ext, Write PIO Ext, Read Multiple Ext, Write Multiple Ext, Read DMA Ext and Write DMA Ext. Which differs from ordinary PIO/DMA command set in only one aspect: LBA register usage. In all HD supports extended LBA, the LBA registers (LBA HIGH, LBA MID, LBA LOW) are implemented as a 16 bits FIFO. On every LBA reigster writing operation the contents in the first 8 bits (MSB) will be swapped into the second 8 bits (LSB). A total 3 16 bits register can support drives up to 128 PB, which maximum 65536 sectors per command.

There is, on the other hand, no physical (electronical) difference between them. That's why most hardware should be able to support drives larger than 128GB by firmware updating. I can actually accessing a 200GB drive by a single 8051 chip.

So partitioning the disk into two won't work as well. It's a problem of ATA command set implementation.

Congrats with the member status

So actually this shoud belong in the hardware forum, or a firmware forum...

Anyway, although it is a firmware matter, my question if this can be "tweaked" or altered is still not answered, and I guess it goes too far to do this?

Thanks for your explanation though!

road2osx · May 5, 2003, 04:55 AM

I don't think we can tweak it without a comprehensive handbook about the hardware.

Tweaking that would need a firmware patch, which means you will have to change the code starting up your Mac and providing some basic mechanism like hardware detection, booting up and kernel loader. I wouldn't dare to so on any machine without a complete register and memory map reference. Even with enough documentation in hand, patching the firmware is a tough task and may leads to some compatibility problem. Also, sometimes the ROM size or memory space makes the implementation impossible.

So I think the answer would be no, at least from my view of point. I can't determine, though, it's infeasible or just difficult.

noisefloor · May 5, 2003, 07:13 AM

So when is apple going to update to support these (will current machines be able to with a firmware update)?

"Big" drives are getting pretty common and cheap, it's a bit surprising that Apple isn't supporting them yet.

Appleman · May 5, 2003, 07:22 AM

Originally posted by noisefloor:
So when is apple going to update to support these (will current machines be able to with a firmware update)?

"Big" drives are getting pretty common and cheap, it's a bit surprising that Apple isn't supporting them yet.

Well, we're talking about an iMac 1999.
First of all it's a consumer machine. It shipped originally with 10 or 13 GB which was considered as quite a lot I guess.

I don't know if PowerMacs from that time could/can have these bigger harddirives, but I'm quite sure they can now. I do not (yet) have a PowerMac (waiting for the 970 models) so I can't confirm this though.

Firmware differs for various machines. My Ti-500 has 3.3.6f5, the iMac DV/SE has 4.1.9.
That doesn't mean the firmware for the TiBook is older, it is just different.

noisefloor · May 5, 2003, 11:26 AM

So do current machines support bigger drives? When did "big" drive support start?

bradoesch · May 5, 2003, 11:38 AM

Originally posted by Appleman:
This baby I have to bring back and change for a 120 GB...

On the bright side, you may have just avoided a severely annoying sleep problem with your iMac. Myself and another member of these boards, plus TONS of people at xlr8yourmac and others at Apple's forums can't sleep their machines with the special edition drives in there. They click (spin up and spin down it sounds like) when the machine is put to sleep. WD claims the drives are fine and it's an issue with Apple, not them. So if you liked putting your iMac to sleep, maybe it's alright that it doesn't work.

Appleman · May 5, 2003, 11:59 AM

Originally posted by bradoesch:
On the bright side, you may have just avoided a severely annoying sleep problem with your iMac. Myself and another member of these boards, plus TONS of people at xlr8yourmac and others at Apple's forums can't sleep their machines with the special edition drives in there. They click (spin up and spin down it sounds like) when the machine is put to sleep. WD claims the drives are fine and it's an issue with Apple, not them. So if you liked putting your iMac to sleep, maybe it's alright that it doesn't work.

Is that for the 120 GB as well? Since I was going to put that one in the iMac tomorrow.

Arkham_c · May 5, 2003, 12:31 PM

Originally posted by noisefloor:
So do current machines support bigger drives? When did "big" drive support start?

I have a friend with a dual-1.25GHz G4, and his machine can't use drives > 137 GB either. I think maybe the XServe is the only one that does support them. What a shame.

Calli46 · May 5, 2003, 01:05 PM

Well, someone at macobserver did just that! I didn't try it myself but then... you may give it a try if you have nothing of value on this drive.
You can read it here

Someone else tried formatting a monster drive in OS 9 for use later with OS X ?

typoon · May 5, 2003, 01:20 PM

What about modifying the Open Firmware? Couldn't you modify it to understand a larger drive? I know on certain models of G4's you can modify open firmware to overclock.

Sarc · May 5, 2003, 06:04 PM

newer XServe's have a better "system controller" (as called by apple) wich handles ATA-133 wich features 48bit addressing, and can handle very large drives with no problems.
The newer PowerMac's also inherited this technology.

Older PowerMac's can't,

tooki · May 5, 2003, 09:51 PM

ATA133 isn't a standard. Only Maxtor makes 133 drives, and even so, 48-bit LBA is NOT a part of any existing ATA standard!!!

As it is, ANY version of ATA can use 48-bit LBA.

It's my understanding that, under OS X at least, Quicksilver G4s and later can use >137GB drives.

tooki

road2osx · May 5, 2003, 11:08 PM

Nope ... ATA-133 and 48 bit addressing IS a standard. I have ATA-6 standard in hand, which defines 48 bit addressing as well as UDMA mode 6 aka ATA-133.

edddeduck · May 6, 2003, 04:28 PM

Apple Tech Notes

Looks like only MDD Macs and X Serves support these large drives.

Cheers Edwin

bstad · May 6, 2003, 05:35 PM

If you go to the Apple.com KnowledgeBase and ask for "large drive support", it points you to article # 86178 which states that the new MDD and XServe support <137MB drives ONLY under OSX 10.2+

edddeduck · May 6, 2003, 05:47 PM

Originally posted by bstad:
If you go to the Apple.com KnowledgeBase and ask for "large drive support", it points you to article # 86178 which states that the new MDD and XServe support <137MB drives ONLY under OSX 10.2+

Well Done!! you just link on the link above?

*jokingly*

Edd

bradoesch · May 7, 2003, 02:04 PM

Originally posted by Appleman:
Is that for the 120 GB as well? Since I was going to put that one in the iMac tomorrow.

Yah, it affects the 120 GB too. That's what one I'm using.

I want a solution!!

Appleman · May 7, 2003, 03:41 PM

Originally posted by bradoesch:
Yah, it affects the 120 GB too. That's what one I'm using.

I want a solution!!

Well, then, never sleep. It;s going to be my jukebox and another back-up disk, so not the real use Mac. But it should be get a solution.

tooki · May 7, 2003, 06:15 PM

Originally posted by road2osx:
Nope ... ATA-133 and 48 bit addressing IS a standard. I have ATA-6 standard in hand, which defines 48 bit addressing as well as UDMA mode 6 aka ATA-133.

OK... last time I checked, ATA-6 hadn't yet been ratified.

But the fact remains that many ATA-5 and ATA/100 controllers support 48-bit LBA despite it not being part of the ATA-5 standard, nor of the ATA/100 "standard."

tooki