It's not all about SSDs when it comes to storage these days. 'Traditional' hard drives are still very much alive as well. Hitachi proves this by introducing the first disks with a capacity of 4 TB. Hardware.Info extensively tested two of them to see how good they are.
You could get the impression that all innovations in terms of computer storage happen in the SSD segment, but conventional hard drive manufacturers have been developing something new as well. In October 2010 we tested the first hard drives with a 3 TB capacity, and now Hitachi has reached 4 TB of capacity.
Hitachi uses five platters with a capacity of 800 GB each, for a total of 4,000 GB. This is step forward in terms of data density, albeit not a huge one. Western Digital has been using four 750 GB platters for a year-and-a-half now for its 3 TB hard drive. This means that Hitachi's new hard drives have a density increase of 6.7 percent compared to the previous most advanced drives. The Seagate 3 TB hard drives have five 600 GB platters.
The 7K4000 and 5K400 are both based on the same platters, so the difference in RPM is what sets the two drives apart. Both hard drives use a SATA 600 interface. The 5K4000 has 32 MB cache and the 7K4000 doubles that to 64 MB.
There is one thing you need to keep in mind with 4 TB and also 3 TB hard drives, and that is that you cannot format the drives according to the traditional MBR (Master Boot Record) system. Instead you have to utilise so-called GPT partitions, which is short for GUID Partition Table. GUID stands for Globally Unique IDentifier. Nowadays this doesn't make a huge difference though, since all SATA 600 controllers are compatible, all recent motherboards use an EFI BIOS, and all new versions of Windows and Mac OS are compatible.
Older PCs and NAS devices could face some compatibility issues, however. Especially with a NAS it is worth checking the manufacturer's compatibility list. If your NAS is suitable for 3 TB then you can assume that the capacity of the 4 TB drive won't pose any problems.