The computer world is going places. From room sized processors to palm tops, everything seems to have revolutionized. As computers decrease in size and increase in complexity, one area that merits constant attention is hard drives. What are hard drives anyway? What makes them so important? Let us investigate hard drives and their characteristics one by one. Hard drives are the primary storage devices of a computer .All data generated by us is saved in these hard disks as electromagnetic information.

A drive is actually made up of platters. Read write heads rotate over platters to write information on them. The four main characteristics of a hard drive are

- read/ write time,

- buffer speed,

- rotation speed and

- interface.

The higher the number of platters, higher the storage capacity. More platters often mean more seek time and hence slower speeds. Recently data storage underwent a sea change with the invention of terabyte drives. These drives are revolutionary because they store data using perpendicular magnetic recording which allocates data more judiciously. Hard drives in the 3.5" form factor typically have a height of 1", which is sufficient to accommodate up to five platters inside the drive. Notebook hard drives use single or twin platter designs and adhere to 9.5 mm or 12.5 mm height limits, though the latter isn't suitable for most notebook designs. We may be having one hard drive already but we may need another for many reasons like:

- Add an additional hard drive, to provide more storage capacity, to provide backup storage capacity

- Replace the system hard drive, by a drive with larger storage capacity

- Buy a hard drive to install in an HDD enclosure, or buy an external hard drive, which is semi-portable (3.5" products) or portable.

3.5" Desktop Hard Drives

The following is a summary of all major drive brands and their merits and demerits. But for understanding them in depth we must first understand the credentials of a hard drive. Standard hard drives for desktops utilize the 3.5" form factor, which refers to the width of the drive. There are models with UltraATA interface or Serial ATA. The latter is more advanced, offers better bandwidth and is much easier to add to your PC, as you do not have to configure the hard drives. Two UltraATA drives have to share one port (referred to as channels), while one serves as a so-called master drive and the other as a slave drive.3.5" hard drives are available at capacities between 40 GB and one terabyte. Performance is determined by the recording technology and the rotation speed, but it is safe to say that the current product generations are clearly faster than their predecessors. The major brand characteristics are:

Hitachi's Deskstar 7K1000 currently is the world's largest desktop hard drive. Its five platters spin at 7,200 RPM and the drive carries 32 MB cache memory. Hitachi uses a Serial ATA/300 interface to communicate with the host system. The drive's performance is excellent, but it is not the performance champion. Other 7,200 RPM drives perform similarly well, and there still is Western Digital's 10,000 RPM Raptor drive, which delivers much quicker access time.

Western Digital's WD5000KS Caviar SE (standing for Special Edition) competes directly against Samsung's Spinpoint T166, which also offers 7,200 RPM and 16 MB cache memory. Its transfer rates are no match for the Samsung drive, but the access time and I/O performance is clearly quicker. According to the datasheets, the WD5000KS also requires less energy than the Samsung T166, but the Hitachi T7K500 is even more efficient.

The WD1600AAJS is interesting because it offers 160 GB storage capacity on a single platter. This ensures very low heat dissipation, quiet acoustics and little moving parts that suffer from wear and tear. It has 8 MB cache, uses a Serial ATA/300 interface, and spins at 7,200 RPM. In addition, this drive starts at only $50 and has a three year warranty.



Maxtor: The two major hard drives offered by Maxtor are diamond max 9 and 10. Like its predecessor, the DiamondMax 10 has a 150MB/sec Serial ATA interface and spins at 7,200 RPM. The drive's seek time and rotational latency are a little faster than the Plus 9, but not by much. The DiamondMax 10 does manage to pack an additional 20GB or storage per platter, though. Additional cache is one of the DiamondMax 10's more notable features, but it's limited to the largest drives. 250 and 300GB DiamondMax 10 drives come with 16MB of cache-twice what's available with 80, 120, 160, and 200GB drives.

Manufacturer

Hitachi / HGST

Maxtor Corporation

Western Digital Corporation

Model

7K250

6Y260M0

WD2500EB

Assembly Family

7K250

DiamondMax Plus 9

Caviar SE

Capacity

HDS722525 - 250 GB

HDS7722516 - 160 GB

HDS722580 - 80 GB

6Y200M0 - 200 GB

6Y160M0 - 160 GB

6Y120M0 - 120 GB

6Y80M0 - 80 GB

WD2000EB - 200 GB

WD1600EB - 160 GB

WD1200EB - 120 GB

Rotation

7.200 U/Min

7.200 U/Min

7.200 U/Min

Interface

Serial ATA 150

Serial ATA 150

Serial ATA 150

Cache

8 MB

8 MB

8 MB

time

8.5 ms

< 9.3 ms

8.9 ms

Seagate may not be able to compete with Hitachi with a terabyte offering, but it was the first hard drive maker to offer a 750 GB drive. The Barracuda 7200.10 still is a huge and fast hard drive, and it is available both with UltraATA and Serial ATA/300 interfaces. Seagate is the only drive maker to offer a full five-year warranty

Samsung's Spinpoint T166 currently is one of the cheapest 500 GB Serial ATA hard drives. It carries 16 MB cache and offers exceptionally high transfer rates. It comes with a three year warranty. The sweetest part, however, is the price tag of $119.99.The Spinpoint T166 utilizes only three instead of four platters to store the 500 GB, which results in less heat dissipation and slightly less noise as well.

Conclusion

The best 160 GB hard drives that can be built with a single platter, e.g. the Western Digital WD1600AAJS, are extremely attractive to OEMs, as they are quick and affordable, and they offer sufficient performance for business users. 500 GB is a storage capacity that will last some time, and it has become fairly affordable to get one of these devices. Samsung and Western Digital have drives that retail at roughly $120, which offer an amazing cost per gigabyte ratio of almost $ 0.25 per GB. Samsung's Spinpoint T166 currently is the fastest 7,200 RPM drive, while Western Digital's WD5000KS offers quicker access time.



When compared to the storage giants, the Seagate Barracuda 7200.10 at 750 GB and Hitachi's Deskstar 7K1000 at 1 TB, the 500 GB segment still look more attractive for us. On the one hand there are no significant performance advantages for the huge drives in the over 500 GB class. Hitachi's terabyte drive is $450, which will almost get you four 500 GB drives.



Thus we have now got the idea about which brand offers which drive and which is more suitable for us. But this knowledge is not sufficient till we know how to maintain our drives. Therefore some important points in this regard are mentioned below.

- Always keep your drive updated and in proper shape

- Do not subject them to improper temperatures like excess heat, moisture etc

- Protect them from sudden spikes and surges.

- Immediately stop working on the drive if you suspect danger.

- Install up to date anti - virus software's.

- Seek professional data recovery help.





Data on the hard drives may be lost due to a number of reasons like virus attacks, hardware malfunction, software backfire or sabotage. Since we may not be able to find out the cause of our lost / inaccessible data, it is better that we approach professionals. These data recovery organizations are often equipped with class 100 labs and technicians who can lift data from even severely damaged drives. Stellar Phoenix Windows Data Recovery Software can fetch for you all your lost, deleted, inaccessible data in cases of logical damages while technicians at their clean rooms can recover data from physically damaged drives.



Computing can be fun if we follow some basic rules of hard ware maintenance. We must pay attention to any unusual noises from our system and watch out for unusually slow speed etc. The hard drives are an intricate network of components. Hence we must never try to doctor our drives. Knowing the basic features of major drives can enable us to figure out the best purchase and thus allowing for confident product purchases. While buying drives we must always weigh our options well because we don't buy one everyday