The 7200.4, as the name suggests, targets the high-performance end of the magnetic drive market, and ships with 16MB of cache.
As for the 7200.11, it'll slot in at the top of that product family. The main difference between the new 1.5TB drive and the 1TB ST31000340AS already available is their platter density. Both disks are four-platter designs, but the 1TB drive uses four 250GB platters, while the new 1.5TB is apparently using four 375GB platters. 375GB seems a bit odd for a platter size, but we've seen multiple manufacturers pushing above 250GB in recent months; Samsung's new 1TB Speedpoint F1 drives now use three 333GB platters instead of the original 4x250GB configuration the drive first shipped with.
The Seagate Barracude 7200.11 will spin at 7,200RPM, and connects via the SATA I interface to achieve 3Gb/s transfer rate as well as a sustained data rate of up to 120MB/s. Of course, the 1.5TB will probably cost a whole chunk of the layman?fs salary, which is why Seagate has other choices for the budget conscious in the form of 1TB, 750GB, 640GB, 500GB, 320GB, and 160GB varieties, accompanied by cache options of 32MB and 16MB.
Well, the Barracuda hard drive will target desktop users, so where does that leave us notebook totters? Thankfully Seagate engineers also have this group in mind, introducing a couple of 2.5?? 500GB hard drives under the Momentus line. These will be available in 5,400RPM and 7,200RPM variations, accompanied by 8MB of cache and 16MB of cache respectively. Both drives will feature free-fall sensor technology to prevent data damage when dropped by parking the heads off the disk whenever it detects any changes in acceleration equal to the force of gravity, all within 3/10ths of a second.