And finally this is the first drive from Hitachi in the 3.5-inch category (3.5-inch is the form factor of desktop hard drives whereas 2.5-inch for laptop hard drives) that features PMR (Perpendicular Magnetic Recording). PMR is used to increase the areal density of the storage media to meet such a large capacity. Perpendicular recording is capable of giving up to 10 times the storage density of the conventional longitudinal recording. Seagate first used PMR in their 750GB hard drive.
Hitachi has used five platters for the 7K1000, each nearly 200 GB. The downside of using five platters is that it affects the response time of the hard drive as well as increases the temperature. The response time of a hard drive is the time between when the data is requested by the CPU to the time the first byte from the hard drive actually reaches it.
We all know how important good marketing is and hard drive manufacturers are no different. Your operating system employs the binary system of zeros and ones and for it 1KB = 1024 bytes, whereas the manufacturers like using the decimal system for advertising the hard drive capacities and according to them — 1KB = 1000 bytes. Consequently, 1MB according to the binary system would be — 1MB = 1024 x 1024 = 10,48,576 bytes whereas according to the decimal system 1MB = 1000 x 1000 = 10,00,000 bytes. This difference rises exponentially as we run into gigabytes. Secondly, formatting the hard drive takes some space off it. Bottom line, the formatted capacity of the drive is 931 GB. That’s almost 70 gigs taken off it and is little less than the formatted capacity of an 80GB hard drive.
Specification Table
| Model | Deskstar 7K1000 |
| Capacity | 1,000 GB |
| Spindle Speed | 7,200 RPM |
| Platters | 5 |
| Cache | 32MB |
| NCQ | Yes |
| Interface | SATA/300 |
| Warranty | 3 years |
| Price | Rs. 19,300 |


