Have you run out of space on your computer? Well it is not as hard as you think to select and replace or add a new harddrive to your system and pretty much instantly gain for space for music, videos, backups, and programs. This article is for regular people who want to upgrade their desktop harddrives. The basic concepts and explanations are relevant to servers and industrials desktops and laptops, but these applications will not be discussed in detail.

The first thing to ask yourself is, "How much more storage space do I need?". Today (Summer 2007) harddrives are measured in Gigabytes (Gb from here on). 1Gb is 1024 Megabytes (Mb) and there are 1024 Kilobytes (Kb) per megabyte. You may still recall that now obsolete storage medium, the floppy disk. A standard 3.5" Floppy contained 1.44 Mb of data. Today iPods and other mp3 players usually contain data storage in Gb because the amount of data we store today is much greater than when we used floppies. On todays market there is only consumer harddrive available over a Gb label, the Hitachi Deskstar 7k1000 which contains 1 Terrabyte (Tb) of storage space which is 1024Gb. The Hitachi drive is priced at $400 retail new whereas a new 40Gb drive is ususally under $40 retail. The answer to how much space you need is usually very dependant on how you use your computer. There are in most cases 3 ways a computer is used.

The first would be as an office or business machine. These machines generally have an Office Suite such as Microsoft Office, Word Perfect, or Open Office. These business related files are generally quite small in the grand scheme of things. Your basic business machine may come with a 40Gb, 60Gb or 80Gb harddrive preinstalled. Office documents are usually between 500Kb for plain text and 3Mb for a large document with images as well. This means that a 40Gb harddrive can store between 13,000 (3Mb) and 80,000 (500Kb) files. Usually to upgrade an office machine a drive with a comparable size to the orignal should be added to the system. This allows for the easiest installation because you can keep everything the same on your primary drive and is truly a plug and play install.

The second type of system is a gaming machine. These are the expensive systems with high end dual core processors, and video cards. Usually for playing highly 3D intensive games. These games take up a lot of space nowadays. In the days of a floppy, and entire program could fit on a single disk. Today a single game can take 1Gb to 2Gb and save files and addons can consume another 500Mb or more. A basic gaming machine purchased 1 year to 6 months ago should have come with a 200Gb to 250Gb hard drive at minimum and 500Gb was the typical maximum. On a 200Gb drive, you can only fit 70-80 games. Gaming machines however, usually also contain images, videos, and basic office software as well. So in reality it may only fit 50 games and then all the typical office application space as well. A 400Gb to 750Gb harddrive would be an ideal upgrade to an existing computer. Try to make the target storage space 400Gb-750Gb either with 1 new drive, or a smaller additional drive.

The final type of computer would be the media PC. This computer is used for multimedia which would be images and videos. These systems may also be used to record television or as securty systems where video is constantly being stored on the harddrive. In the world of the media PC, bigger is better! It may be hard to fathom, but a single 1 hour HDTV stream with surround sound can take 9.5Gb of space. That means a 200Gb drive can store 21 hours of video. That is not a whole lot. 20 TV episodes, and 6 movies later your entire harddrive is full. You can encode video into more loss-filled or compressed video formats and then an hour comes out to around 1Gb, but the quality difference is there. That being said, get the biggest drive you can afford. It is not uncommon to have multiple harddrives linked together for total space in the Tb range (1024Gb).

After you have decided how much sotrage space you want, you will be given the option for IDE, SATA, SCSI, and other formats. If you have a general computer as described above and not a server or industrial PC, then there is almost a 99% chance that you have either an IDE or SATA format drive. Most newer computers have slots to take both types of drives, whereas older computers have all IDE. SATA is the newcomer, while IDE has been around since the days of the AT computer. The easiest way to tell what type of harddrive you have is to look at the cable. SATA is a thin flat noodle shaped connector. In most Dell computers the cable is red or orange. About 1/2" wide by 1/8" thick. IDE cables on the other hand are huge in comparison. They are long ribbon cables with a connector that takes up almost half of the back of your harddrive. Usually 2" wide by 1/4" thick at the connector. The first connector is an IDE conenctor and the second is a SATA connector.

eBay has categories to narrow down your search on harddrives to either SATA or IDE, so once you figure it out which you need, pick that category and it will make your searches easier. The prices are usually within a few dollars of eachother.

Some other things that you might see to grab your attention with both types of drives is the speed measured in RPM's. Just like your car that has RPM (revolutions per minute), harddrives do the same. That is the "whirr" sound you hear. Common speeds are 5400rpm, 7200rmp, 10000rpm, and 15000rpm. The faster the drive spins, the faster data can be written and retrieved. 7200 rpm is more than fast enough for the office machines and gaming machines. Even though some gamers might believe they need the 10k or 15k rpm drives, they dont unless they want to play their games while downloading in the background, and encoding video. The higher speed drives are usually reserved for media PC's where there is constant data flow from a recording device to the drive and a hiccup could cause a frozen frame or glitch in the recording and also higher speed drives are used in servers and industrial machines. 7200 is the most common, and the cheapest. 5400 is for older laptop drives because the fewer rpm, the longer the battery will last.

Another thing that will be brought up is data transfer speed. For IDE drives this will be ATA100 or ATA133. As with the rpm's above, the faster the data transfer, the faster data can be written to and read from. ATA100 is obsolete now but there still may be drives popping up on eBay because ATA133 is the same price now and faster. ATA100 and ATA133 will both work on all modern computers interchangeably. As for SATA drives, you will get 1.5 and 3.0 speeds. These too will work interchangeably, however, if your computer does not support SATA 3.0, then it will operate the drive at 1.5 speeds, so it is a waste of money. In general, dont use speeds as a buying consideration. If you win a drive with a faster speed then woohoo, but it should not be something that makes you want one drive over the other. In all actuality, you will never ever use all the bandwith available on SATA drives for anothe few years to come. No office computer will benefit from this. Not even media PC's or gaming machines will benfit greatly from it. It may mean the difference in milliseconds (1/1000th of a second is a millisecond) between files opening up. To give a reference point, when you do your fastest double click to open an application, it takes 300 milliseconds and when you blink your eye it is 25 to 50 milliseconds. So dont waste your money.

The fina consideration is new, used, or refurbished. Hard drives will usually get 3 years or more out of them before they fail. Some will fail gradually and start to make a grinding or beeping noise for days or even months. If that happens, backup your data and buy a new drive. Some drives like the Hitachi Deskstars are nicknamed "Deathstars" after Star Wars because their failure rate is so high. Generally, new and used drives will both work fine. If it is a refurbished drive, look up some product reviews on the internet and see how many people complain of failures for that model. If it is high, then you can bet that is why it was returned and fixed and being sold as a refurb.

So now that you have your new harddrive, you stare at it blankly and figure out how to put it into the magical computer box. The first thing to do is to remove the side of the computer case. There will be 2 to 4 phillips screws on the back of your computer very close to the edge holding the case on the side. On most computers including Dells, if you look at the back of the computer, the screws you want to remove are on the right hand side. Once those screws are out, you usually just pull the side towards the back and then it slips out. Just jiggle it a bit and it will become obvious how to get it out.

Nopw you should see either an SATA or IDE cable. Follow that to the harddrive bay. Usually the harddrive bay is underneath the CD drives, and floppy drive or card readers. If the cable is IDE, then check to make sure there is a free connector. 1 IDE cable can connect 2 drives, whereas 1 SATA cable can only go to 1 drive. If there is not a free IDE connector then follow that cable back to the motherboard. The motherboard is the big exposed circuit board that everything connect to. It is screwed into the case vertically and all wires run to it. Where that IDE cable connects there might be another port by it. If so, use that to connect your harddrive. If there is not, then you will need a cable with a primary (hard drive #1) and secondary (hard drive #2) conenctors. If the inital cable you found was SATA, then follow that to the motherboard and that is where you will plug in the cable to go to your new harddrive.

If your harddrive is IDE, then on the back there will be some pins with a jumper on them and a diagram on the drive's top. One will be Cable Select or abbreviated as CS, another will be Master (MS or MR or MSTR), and the final will be Slave (SL or SV, or SLV). For CS to work, then both drives will need to be in CS mode. This is basically an automatic detection mode and the computer will decide what is best. If your hard drives and motherboard supports this, then it is reccommended to use it. Otherwise you will need to choose either Master or Slave. If you are adding another drive to your system, then make sure your primary (old) drive is set to Master, and set the new drive to Slave.

The final steps are to screw the drive into the bay with 4 phillips screws, and then connect either the SATA or IDE cable to the back and then to the motherboard. All harddrives require power as well, so tkae a free power connector that is dangling in the case, and plug it in. All wires will only fit 1 way, so if it doesnt want to go in, flip it around and try again. Dont force it.

And there you go! You have bought and installed a new harddrive in less time than it would take you to drive to your local computer store and for half the price.