EFI is not necessary for greater than 2TB boot recognition. Now as soon as I find the link where they are implementing this for W2K3 I'll post it.
Sorry, but jamesgoddard is correct. EFI is most certainly necessary for boot partitions to reside on a device with > 2^32 blocks (2TB).
The quotes you refer to are correct for large (> 2TB) arrays in general when used as data-only arrays, not boot arrays.
I recently set up a Windows Server 2003 with a 6TB iSCSI array, and learned a few things while I did it. 8)
Here is a summary:
1. The only versions of Windows that support >2 TB arrays at all are Windows XP x64, Windows Server 2003 SP1 (x86 and x64), and Windows Vista (x86 and x64).
2. The only versions of Windows that can use a >2 TB array as a boot device are Windows Vista and the not-yet-released Longhorn server. They can only do this on a system with an EFI BIOS.
Any system with a standard PC BIOS cannot boot from a >2 TB array regardless of operating system.
3. To support an array >2 TB, the device must be converted to a GPT disk in Windows Disk Management.
4. To support a device >2 TB, the controller must support some type of extended addressing mechanism (48-bit LBA for IDE/SATA devices, 64-bit LBA / 16-byte CDB for SCSI API-compatible controllers). If the controller doesn't support this, the maximum array size it can support is 2TB.
5. Some controllers will assist you in hooking up a large array to an operating system that doesn't support it (such as Windows XP) by using LUN carving. Using this, a large array appears to the computer as multiple 2TB arrays. Each 2TB virtual array can then be formatted as a standard MBR disk. Of course, not all of your space will be on one volume.
6. The FAT32 file system is not supported on arrays >2TB. Volumes >2TB must be NTFS. NTFS will support up to a 256TB array in its current implementation.
7. It is recommended that >2TB arrays be basic disks unless absolutely necessary to make them dynamic disks. Dynamic disks are only supported on devices that are direct connected or connected on a SAN through a Fibre Channel card or iSCSI hardware card. Dynamic disks are not supported using the Microsoft iSCSI software initiator.
8. Some RAID controllers and SAN units have a hack that is supposed to let them get around the 2TB limit on operating systems that don't support it. To implement it, they increase the sector size from the standard 512 bytes up to as large as 4096 bytes. Using this, they purport to be able to support up to a 16 TB array as an MBR disk.
Do not use this mechanism under Windows. Windows specifically does not support any device with a sector size other than 512 bytes. Under Linux OS's, this should work OK.