We knew they were coming soon, just not sure exactly when. Today marks the day the world's first 4TB capacity HDD hits the scene with Seagate beating its competitors out to the milestone. However, the it isn't in naked form at this time and comes as part of their GoFlex Desk external HDD family.

The official announcement from Seagate on the new unit doesn't go into specifics about the 4TB 3.5-inch drive itself, but we are presuming it uses a 4x1TB platter arrangement. As for specific features on the 4TB GoFlex Desk, it uses USB 3.0 for its connectivity and comes pre-loaded with software to assist in automatic, continuous data backup (with encryption) and the included adapter has an illuminited gauge that makes it quick and easy to look at the available space remaining on the drive.

Seagate is now shipping the USB 3.0 4TB GoFlex Desk with a price tag of $249 US. There's word of a Mac version on the way too, shipping later this month with FireWire 800 and USB 2.0 connectivity.

Now we just have to wait for the likes of WD and others to jump aboard the 4TB bandwagon and for multiple bare drive launches that are all inevitably on the cards by the end of Q4.