The Technical Issue
A computer needs to know where to put data on your hard disk, and where to retrieve it. That's what LBA does, it assigns addresses to each 512-byte block on the hard drive. This is the smallest physical block of data on the hard drive. The problem is that the LBA standard simply runs out of address space at 2.1TB. A PC running on classic LBA is unable to address a disk larger than that. In fact, according to Seagate, some wonky things can happen if you try to use a larger disk. Some systems may report the drive size as being only 990MB.The key to solving this problem is the Long LBA scheme. The Long LBA standard increases the number of bytes per block allowing more addressable space. You'll be happy to know that many modern PCs can take advantage of this. All 64-bit versions of Windows Vista and Windows 7 can recognize drives with Long LBA. Some modified versions of Linux can also utilize Long LBA. However, even on these systems there is a caveat. The new 3TB drives probably cannot be used as a boot drive. Many motherboard BIOS don't support a GUID partition table capable of using drives larger than 2.1TB for the master boot record. Only motherboards with UEFI instead of a BIOS will work--but that's a more complicated topic we'll explain in a later guide.
So, this incredibly huge drive very well may work in your system (but not as a boot drive). But what's the advantage of moving to larger and larger disks? Many would assert in this day and age that server side, or "cloud" storage is the way to go. There are reasons both for and against using these increasingly large drives to keep everything locally.
Data Security
Let's face it, you're most likely not an IT pro. Being on this website certainly marks you as a proud technology enthusiast for sure. But managing large amounts of data can get complicated very quickly. Storing that data on a server somewhere online can take that burden away. Products like Amazon S3, Carbonite and Dropbox have shown us that online storage and backup can be done easily. This is really the big advantage for online storage. You don't have to manage it yourself.
If you're the paranoid sort, there's a down side to cloud storage though. It's likely that your data is living in a server room with other people's data. If the server were compromised or seized in a legal action (to which you are unrelated) you could be hurting. Going with a company you trust can alleviate this concern. Reputable online storage/backup companies use end-to-end encryption to keep customer data safe, so data theft is unlikely. But some may never feel truly safe with their data under someone else's physical control.
Accessibility
But it's not all roses in cloud storage land. You have to make some tradeoffs to get that security and peace of mind. First is the concern of data accessibility. When your data is only available on a remote web server, you need an internet connection to do much of anything. Even if you count on mobile broadband via a cell carrier, spotty reception can render your PC useless without access to your data. Without an internet connection, the data on your local drive is still accessible.Still, it might be nice to have access to your data from more places. That's something server side storage can offer. If you aren't at your computer, you can most likely access your online server to use your files. A good example of the usefulness of this is Dropbox. You can sync data between your computers and access files through their web interface. The cloud offers the ability to use your data without bringing your hard drives along for the ride.
Speed
If you manage to get one of those neat 1Gb/s Google fiber lines, you'd have a bit more breathing room. Then you're limited by the speed of your wireless connection. Wiring in via Ethernet you're still limited by the 1 Gigabit ports on most routers. Compare that to the 6Gb/s speeds of new SATA drives. If you were backing up your DVDs, for instance, the amount of time it would take to upload all those to a server would be unreasonable. Barring some magical increase in connection speed, you will never be able to manipulate files as efficiently with cloud storage as you can with a local drive.
In many ways, these large disks are better suited for use in a server environment. Few of us create sufficient content that we need this sort of storage. Even if you do, the logistics of backing up that much data could make your head spin. Short of buying a duplicate of each disk for RAID, there's little to be done. But risking a bit of data security does gain you much better speed on local disks. Not to mention access to your files in the absence of an internet connection. There are advantages of each; for now we're going to keep rocking local drives, but it can't hurt to put some stuff in the cloud for safe keeping. Do you have need for larger hard drive? What are you putting on those things anyway?