Bjorn3D posted a review on the Seagate Barracuda 7200.12

As the platter density increases, hard drives are able to pack more data per disk and, as a result, the time for data retrieval is shorter due to less time that is needed to find the bits of data. Not only that, hard drives are able to perform faster. The larger areal density also allows hard drive manufactures to exceed the storage capacity of 1TB and now we are seeing HD manufactures breaking into 1.5TB and even 2TB. Seagate’s latest Barracuda 7200.12 is the company’s first hard drive that comes with 500 GB platter density.

Seagate Barracuda 7200.12 Review