Is there any speed difference between APM and GUID partition tables?

NazgulRR

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Oct 4, 2010
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I just got a WD MyPassport Studio 1TB drive for backup purposes (1:1 clone of my OSX Lion drive in my MBP) and it came pre-formated in APM. I noticed this only AFTER spending 7 hours of backing up all of my data to it.
I can boot cloned OSX Lion from it normally, but it's not very fast (FW800). I am just wondering if it would be any faster if I re-formatted it to GUID table?

File system is HFS+ (Journaled).


PS: I use part of that WD MyPassport Studio for external storage. Would I benefit anything by going from APM to GUID? Again, the partition is HFS+ (Journaled).
 
Last edited:
Nov 28, 2010
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Disk Utility has this to say, thus my wondering (or as it is now written "wandering"), why you can even boot from it:


And is that HDD you bought a "Mac Edition" of that HDD? Normally HDDs come pre-formatted with NTFS and MBR as partition map scheme.
 

Intell

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Jan 24, 2010
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I have never known any Intell Mac to be able to boot from an APM drive. Having just tried it, nothing happens. My Blackbook refuses to boot from my Snow Leopard clone.
 
Nov 28, 2010
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I have never known any Intell Mac to be able to boot from an APM drive. Having just tried it, nothing happens. My Blackbook refuses to boot from my Snow Leopard clone.
How the **** can yo clone this fast? And is Intel the same as Intell for you? Or is that just a major slip-up?
 

NazgulRR

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Original poster
Oct 4, 2010
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And is that HDD you bought a "Mac Edition" of that HDD? Normally HDDs come pre-formatted with NTFS and MBR as partition map scheme.
Yup, Mac Edition. APM and HFS+ (Journaled).

I have never known any Intell Mac to be able to boot from an APM drive. Having just tried it, nothing happens. My Blackbook refuses to boot from my Snow Leopard clone.
Yup, cloned my OSX Lion drive to it. It boots up fine. Was just wondering if using GUID would improve speed.

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Follow up question: If I ever decided to install Bootcamp on my Macbook alongside OSX Lion and then had this cloned over to the APM clone, would I be able to boot both OSX Lion and Bootcamp Windows from that clone?
 

Intell

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Jan 24, 2010
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How the **** can yo clone this fast? And is Intel the same as Intell for you? Or is that just a major slip-up?
It's a daily Carbon Copy Clone disk that supports one of my Macs. I just ejected it and plugged it into my Blackbook. Spelling the CPU maker's name with a second L is just something I do on here.
 
Nov 28, 2010
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It's a daily Carbon Copy Clone disk that supports one of my Macs. I just ejected it and plugged it into my Blackbook.
I still don't understand (maybe I am a bit daft), how a Snow Leopard clone, which clearly runs on an Intel Mac (unless you meant Leopard), can't boot from a BlackBook. I guess you cloned a PPC Mac via CCC onto an AFP partitioned HDD and tried to boot it via an Intel Mac (the BlackBook).

As to your not so major slip-up, but your habit, I guess I have noticed it before, but was too afraid to ask. ;)

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Follow up question: If I ever decided to install Bootcamp on my Macbook alongside OSX Lion and then had this cloned over to the APM clone, would I be able to boot both OSX Lion and Bootcamp Windows from that clone?
Windows installed via Boot Camp will not be cloned, as CCC needs HFS+ formatted volumes to clone to, regardless of the partition map scheme.
 

NazgulRR

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Oct 4, 2010
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Windows installed via Boot Camp will not be cloned, as CCC needs HFS+ formatted volumes to clone to, regardless of the partition map scheme.
Shouldn't be a problem than as I said that the drive is in APM and the partitions are HFS+ (Journaled).
 
Nov 28, 2010
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Shouldn't be a problem than as I said that the drive is in APM and the partitions are HFS+ (Journaled).
I should have been clearer. Windows uses NTFS as file system, it will not be cloned via CarbonCopyCloner or SuperDuper!, as they only clone from and to HFS+ formatted volumes, thus Windows is excluded. Maybe take a look at WinClone, though is no longer developed.
 

Intell

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Jan 24, 2010
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I still don't understand (maybe I am a bit daft), how a Snow Leopard clone, which clearly runs on an Intel Mac (unless you meant Leopard), can't boot from a BlackBook. I guess you cloned a PPC Mac via CCC onto an AFP partitioned HDD and tried to boot it via an Intel Mac (the BlackBook).

As to your not so major slip-up, but your habit, I guess I have noticed it before, but was too afraid to ask. ;)
The drive is partitioned in APM and was once attached to my Cube and had a CCC cloned Leopard on it. I just carried it over to my Mac Mini when I replaced my Cube and cloned Leopard on to my Mini from it. Over the years Carbon Copy Cloner has upgraded the external APM drive to Snow Leopard. Never needed to boot from it and it never occurred to me to switch it to GUID. Should probably do that...
 
Nov 28, 2010
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The drive is partitioned in APM and was once attached to my Cube and had a CCC cloned Leopard on it. I just carried it over to my Mac Mini when I replaced my Cube and cloned Leopard on to my Mini from it. Over the years Carbon Copy Cloner has upgraded the external APM drive to Snow Leopard. Never needed to boot from it and it never occurred to me to switch it to GUID. Should probably do that...
Ah, thanks for the explanation. Now I can sleep, or as they say on Capilar, flood to the sea.
 

NazgulRR

macrumors 6502
Original poster
Oct 4, 2010
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I should have been clearer. Windows uses NTFS as file system, it will not be cloned via CarbonCopyCloner or SuperDuper!, as they only clone from and to HFS+ formatted volumes, thus Windows is excluded.
Oh, right. So in any case Bootcamp partition is not cloned. This is clear now.

So if I am able to boot the OSX clone from the APM drive, is there anything I am missing out by not having it in GUID?
 

Intell

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Jan 24, 2010
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Oh, right. So in any case Bootcamp partition is not cloned. This is clear now.

So if I am able to boot the OSX clone from the APM drive, is there anything I am missing out by not having it in GUID?
Support for booting most (all) Intell Macs and some GUID only disk utilities.