Formatting external HDD?

Use ExFAT.
If you have a file over 4GB, it just wont transfer.
Ive formated all my USBs into ExFAT which bypasses the 4GB limit and still have compatibility to Windows.

 

Format A Hard Drive Using Disk Utility (which is in your /Applications/Utilities folder)

Choose the appropriate format:

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 OS X system files.
  [*]To Read/Write HFS+ from Windows, Install MacDrive
  [*]To Read HFS+ (but not Write) from Windows, Install HFSExplorer
• Maximum file size: 8EiB
• Maximum volume size: 8EiB
• Mac OS X: Mac OS Extended format (HFS Plus) volume and file limits
• 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)

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 ($19.95) (Best Choice for Lion and Mountain Lion)
  • For Mac OS X 10.5 and later, including Lion, FUSE for OS X
  • For 32-bit Mac OS X, install NTFS-3G for Mac OS X (free) (does not work in 64-bit mode)
  • Some have reported problems using Tuxera (approx $36), which is an enhanced version of NTFS-3G with faster performance.
  • Native NTFS support can be enabled in Snow Leopard and later versions, 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.

exFAT (FAT64)

• Supported in Mac OS X only in 10.6.5 or later.
• Not all Windows versions support exFAT. See disadvantages.
• 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.

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.

 

I use Paragon NTFS for the Mac and HFS+ for Windows. It's brilliant. It allows me to use disks that are ideally formatted for their native computer and easily connect them to the other system when I want. (www.paragon-software.com/home/ntfs-mac/)

I also bought a Firewire800 card for my PC so I don't have to drop down to USB 2.0 speed when using my Mac drives on the PC.