Hard Drive Page

Description:

As the primary communication device to the rest of the computer, the hard drive is very important. The hard drive stores most of a computer's information including the operating system and all of your programs. Having a fast CPU is not of much use if you have a slow hard drive. The reason for this is because the CPU will just spend time waiting for information from the hard drive. During this time, the CPU is just twiddling it's thumbs...

What To Look For:

First, look at the technology. Do you want IDE or SCSI (see Glossary for definitions)? SCSI is the faster interface which also takes a load off of your CPU. It also requires the use of a SCSI Card. IDE is the more common hard drive interface. It is also less expensive. For common users, IDE is probably sufficient. However, if you work with a lot demanding applications and games, SCSI may be the way to go, if you can afford it. Very few retail computers are buit around the SCSI interface. This is one of the reasons you may want to Assemble your Computer. If you can afford to go SCSI, you should then get a SCSI CD-ROM drive since they aren't much more expensive if they are SCSI.
*Update* For the most part, IDE is catching up with SCSI in speed. The primary reason to go SCSI anymore is if you want a lot of devices (you can only have 4 IDE devices), you really need the high speed 10,000 RPM drives, or you want a CD-ROM burner. CD-ROM burners work best when they are SCSI, and they work best along with a SCSI hard drive and CD-ROM drive, particularly for making CD to CD copies.
Next, if you decide to use IDE, look for UDMA/33 or Ultra ATA or UIDE, all of which are the same thing and mean that the drive is capable of transferring data at a faster rate (33 MB/s). All motherboard chipsets from the TX on support UDMA.
If you decide to use SCSI, you need to consider the type of SCSI (yes, it gets more complicated). These are hard to define since different companies represent them differently. They consist of a mix of SCSI-1, SCSI-2, and SCSI-3 as well as Narrow-SCSI, Ultra-SCSI, Ultra2-SCSI, Wide-SCSI, and Ultra-Wide-SCSI. The simplest way to decide is to look at the number of pins your controller has. If it has a 68-pin connector, then it has Wide capability. Find a hard drive that has a 68-pin connector and then look for the highest SCSI rating and/or the highest in the list above, with "Ultra-Wide-SCSI" being the highest.
*Update* Ultra2 Wide SCSI is now the fastest... There isn't a large speed improvement though. However, the newest U2W controllers are very fast and reliable (such as Adaptec's 2940U2W).
Of course, you need to consider the size of the drive. Although one can get by with 2 GB of hard disk space, you'll be much happier with 6 GB or more. Consider 4.3 GB a minimum amount unless you plan to perform a lot of disk maintenance and uninstalls.
Whatever you've decided you now need to look at the rpm (revolutions per minute) of the drive. A minimum to look for is 5400 rpm. This is basically the standard for IDE. 7200 rpm IDE drives are starting to show up though, such as Seagate's Medalist Pro. They aren't much more expensive, so you may want to get one of them. If you're going SCSI, consider 7200 rpm as a minimum to make it worth the extra cost (although a 5400 rpm SCSI drive will probably be faster than a 7200 rpm IDE drive, not to mention the additional benefits of SCSI). Currently, SCSI maxes out at 10,000 rpm with the Seagate Cheetahs and IBM's new UltraStar 9ZX drives (the IBMs are currently over $1000 though).
Next, look at the amount of cache on the drive. Usually they have about 128kb, 256kb, or 512kb of cache memory. Some SCSI drives have 4 MB of cache (IBM 9LZX). I would advise trying to find one with 512kb.
The final thing to look at is access time. Usually if you have a high rpm drive, the access time will be pretty low too. However, if you're looking at two hard drives with the same rpm, definitely go for the one with the lower access time. Any drive with less than 10 ms (milli-seconds) access time should be sufficient. Access time is the time it takes for the heads that read the hard drive's data to get to another part of the disk.

Recommendations:

6/16/00 Update - IBM's 75 GXP is now the king of 7200 rpm IDE hard drives. Its quiet operation combined with incredible speed and past brand reliability make it the drive to beat. Quantum's Fireball Plus LM is another great drive, with similar performance scores but louder. Either drive would make a great choice.
1/17/00 Update - I just wanted to note that my recommendations, though old, still hold. There are some better drives out there, but not by a significant margin. There hasn't been many great advances in the hard drive area lately. If you are looking for the fastest IDE drive, you may want to get the Maxtor DiamondMax Plus 40, which does show a significant speed advantage over the IBM listed below.
10/10/99 Update- My current "best pick" would be the IBM 22GXP IDE hard drives. They are cheap compared to SCSI, and now fairly inexpensive for IDE. This drive runs at a fast 7200 rpm. It even has 2 MB of cache, but it is also much more expensive. The 14GXP is another incredible hard drive. It's a little slower than the 22GXP, but also very cheap ($150 for 14 GBs of 7200 rpm speed)!
Others to consider are the Western Digital Expert (7200 rpm and ATA-66), the Maxtor DiamondMax Plus 5120 with 1MB cache (7200 RPM and ATA-33), and the Western Digital Caviar (model number ACS313000 - 5400 RPM and ATA-66), in that order! I only recommend the Caviar because it is a good drive for a very low price.
1. 1/17/00 Update- For SCSI drives, I have several recommendations depending on your budget (all of which support 68-pin Ultra2Wide). First would be the 9 GB Quantum Atlas IV (which is now fairly cheap). It beats out my second pick which is IBM's UltraStar 18ES. It is one of the most affordable 7200 rpm SCSI drives and also one of the fastest. The Seagate Barracuda drives are also fairly inexpensive. They run at 7200 rpms and have an access time of 8 ms. They are a little more expensive than the others and a little slower too.
2. The IBM UltraStar 9ES is a cheap lower-end SCSI drive. It is one of the more affordable SCSI hard drives and one I would recommend.
3. 10/10/99 Update- The Quantum Atlas 10k now beats out the IBM 9LZX in both price and speed! It's a 10,000 rpm hard drive that can be had for under $500!
The IBM UltraStar 9LZX is the second best at this point in time, but it is not affordable by most people's standards. It runs at 10,000 rpm, has an access time of 6.3 ms, and has 4 MB of cache, along with a high price tag...
3. If you can afford it, the Seagate Cheetahs run at 10,000 rpms and have an access time of 7.5 ms. They vary in the amount of cache they have, with the 9GB having 1 MB and the 4.3 GB having 512k cache.
4. Also worth mentioning is Quantum's Atlas III which uses the new Ultra2-SCSI technology that doubles the maximum throughput to 80 MB/sec. It's 7200 rpms and a 7.8 ms access time. It's also quite expensive.