Any difference between a new external hard drive pre-formatted for mac and one I have to format myself as it was pre-formatted for windows?

PsychoMedic wrote:

I could return it and get one pre-formatted for mac but is that necessary?

No.

I could just format this drive and save a trip to the store.

Yes.

What would I gain by switching this drive for a new mac-formatted drive other than having to go through the reformatting procedure?

Nothing.

When you get your new MBP, open Disk Utility>Erase and format the external HDD to Mac OS Extended (Journaled). Then it will be ready for use.

Ciao.

3TB USB 3.0 external hard drive new in the box that is pre-formatted for windows.

Exactly what make/model drive is it? Check the drive's specs & manual carefully before opening the box to make sure it supports Mac OS Extended formatting..

This is important, because as unbelievable as it sounds there are still some drives on the market that are designed for Windows only and cannot be formatted for Mac. Latest one I ran into (just last week) is the Seagate Expansion drive.

What would I gain by switching this drive for a new mac-formatted drive other than having to go through the reformatting procedure?

A drive that is pre-formatted as Mac OS Extended, or that you format yourself as Mac OS Extended, gives you:

• Full read-write capability (unavailable under PC/NTFS unless you add a 3rd party app such as NTFS for Mac)
• Compatibility with certain apps that require Mac OS Extended formatting for storage (Final Cut comes to mind)
• Support for large files (not available under PC/FAT)
• Ability to boot OS X
• Ability to use the drive as a Time Machine backup drive

PsychoMedic wrote:

I have a 3TB USB 3.0 external hard drive new in the box that is pre-formatted for windows.

What does the format say on the box?

If it's exFAT, then you don't have to do jack squat, will work as a file drive between Windows and Macs.

If it's FAT, then you don't have to do jack squat, will work as a file drive between Windows and Macs., but only up to 4GB sized files.

If it's NTFS, then you do have to reformat it as the Mac can only read, but not natively write to NTFS without paid third party sofware which will require paid upgrades and possibly break during OS X updates and upgrades.

If you plan on making the drive a TimeMachine or bootable clone for your Mac, then it has to be formatted 1 Partiton, Option: GUID and OS X Extended Journaled (JHFS+) in Applications > Utilities > Disk Utility.

This format (JHFS+) cannot be read by Windows without MacDrive first being installed on the Windows machines.

TimeMachine drives cannot be used with Windows machines as there is no Windows version.

So it depends what you intend to use the drive for, as backup then you have to choose JHFS+, for file drive between Mac's and PC's, then exFAT or FAT formatted on the Windows PC.

I know the temptation with a large drive is to use it as both backup and file drive by partitioning the drive, but I don't advise this as your backup is your lifesaver and file transfer drives tend to get lost, dropped etc.

Read through my many User Tips here and get up to speed

https://discussions.apple.com/community/notebooks/macbook_pro?view=documents

PsychoMedic wrote:

It is a WD My Book [ WDBFJK0030HBK-NESN ]. On the box it says "Requires reformatting for Mac OS X". It is preformatted NTFS.

Can I format it as Mac OS Extended using the MBP utility?

Yes.

Ciao.

If it's exFAT, then you don't have to do jack squat, will work as a file drive between Windows and Macs.

It will work, yes, but I wouldn't advise any one to use it. No journaling, limited permissions support, reports of instability, issues with encryption & compression. I wouldn't trust my data on one.

ds store At the center of the Dark Zone

If it's exFAT, then you don't have to do jack squat, will work as a file drive between Windows and Macs.

Not yet SEEN one new in box ever formatted in ExFat

Format it for MAC OSX EXTENDED JOURNALED for your Mac.

FAT32 (File Allocation Table)

• Read/Write FAT32 from both native Windows and native Mac OS X.
• Maximum file size: 4GB.
• Maximum volume size: 2TB
• You can use this format if you share the drive between Mac OS X and Windows computers and have no files larger than 4GB.

NTFS (Windows NT File System)

• Read/Write NTFS from native Windows.
• Read only NTFS from native Mac OS X
• To Read/Write/Format NTFS from Mac OS X, here are some alternatives:

  For Mac OS X 10.4 or later (32 or 64-bit), install Paragon (approx $20) (Best Choice for Lion)

  Native NTFS support can be enabled in Snow Leopard and Lion, but is not advisable, due to instability.

• AirPort Extreme (802.11n) and Time Capsule do not support NTFS
• Maximum file size: 16 TB
• Maximum volume size: 256TB
• You can use this format if you routinely share a drive with multiple Windows systems.

HFS+ (Hierarchical File System, a.k.a. Mac OS Extended (Journaled) Don't use case-sensitive)

• Read/Write HFS+ from native Mac OS X
• Required for Time Machine or Carbon Copy Cloner or SuperDuper! backups of Mac internal hard drive.
• To Read HFS+ (but not Write) from Windows, Install HFSExplorer
• Maximum file size: 8EiB
• Maximum volume size: 8EiB
• You can use this format if you only use the drive with Mac OS X, or use it for backups of your Mac OS X internal drive, or if you only share it with one Windows PC (with MacDrive installed on the PC)

EXFAT (FAT64)

• Supported in Mac OS X only in 10.6.5 or later.
• Not all Windows versions support exFAT.
• exFAT (Extended File Allocation Table)
• AirPort Extreme (802.11n) and Time Capsule do not support exFAT
• Maximum file size: 16 EiB
• Maximum volume size: 64 ZiB
• You can use this format if it is supported by all computers with which you intend to share the drive. See "disadvantages" for details.