How to Choose a Hard Drive?

• What is new on the horizon? SSD - solid state drive. It is similar to the USB thumdrives or digital camera flash cards but many, many times faster with more capacity, also is more expensive. The flash type of memory used in these drives is the latest technology and the fastest created flash memory to date. It is much faster than SATA drives, doesn't have mechanical parts to fail, and draws only a fraction of power vs. regular hard drives that need power to spin. This recent technology has only two side effects, it is too expensive for a regular user and its reliability is not yet conclusive. The downside of SSD drives is that writing wears the drives out little by little. However, with technological advances a few years down the road might replace rotating hard drives once the prices will fall.
  
  
• Serial ATA interface is the way to go nowadays! The transition from SATA to IDE drives is almost complete. SATA holds more than 90% of market share. Today all modern power supplies come with SATA power connectors to support the establishing format. Just as well, all modern motherboards now have built-in SATA controllers and some include SATA cables. IDE ports disappear from small factor motherboards and soon will not be included for compatibility due to the age of the IDE technology. The IDE would have found its demise sooner but cheap optical drives were manufactured as IDE to keep the costs down, prolonging the dependence on this format in regular day-to-day systems.
  
  
• SATA technology is cheaper than IDE, uses narrower cables and easier to connect. These features make the choice clear. Two years ago the choice was not so obvious. The following paragraph is what we used to say:

  Normal hard drives like we are all used to using are Parallel ATA (PATA). There is a new standard called Serial ATA which boosts transfer speeds up to 150MBs [and up to 300MB/s bursts with SATA2 technology) as opposed to a max of 133MBs with parallel interface. The SATA standard also improves airflow in the case because wide ribbons are no longer needed and a somewhat thin compact cable is used instead. Additionally, SATA2 offers a few features like Native Command Queuing, eSATA and other. However - using SATA means you will need a SATA controller, a SATA drive, and a SATA power cable/adapter (often not included on power supplies yet). The actual speed improvement of SATA vs PATA is not much noticeable with current drives unless you are talking about the high end SATA drives using RPMs higher than 7200 which can burst through a wider channel than PATA. If you are building an average/upper end system there is currently no pressing reason to go SATA unless you are building for the future. PATA standard is slowly dying out and high-end motherboards stop even including PATA support for hard drives, they still include one, though, for CD-ROM/DVD-ROM drives that are still in their majority use PATA interface. For more information please see: PATA vs SATA.

  Today is the day when SATA is no longer seen as a future, the future has arrived and SATA is dominating.
  
  
• There is only a small price difference among 320, 500 and even 750 GB hard drives. We suggest getting as large a hard drive as possible if you don't care to spend $10 or $20 more for 50 to 250GB more space!
  
  
• If you are working with a limited budget then a 250GB or 320GB drive is plenty for many people! However, people buy 500GB HDD more often because this size offers the best price per a gigabyte today.
  
  
• How to calculate what is the best deal price-wise? Let us show you an example. Say, you have one hard drive 320GB for $42.99 and a second 500GB hard drive for $51.99. You want to know which one is the best deal. Thus, we have to find a price per gigabyte in each unit. The one that has the lesser price per gigabyte would be the ultimately best deal. So, $42.99/320GB = $0.134 or 13 cents per gigabyte. Then, $51.99/500GB = $0.103 or 10 cents per gigabyte. Thus, gigabyte-wise it is evident that 500GB is a cheaper solution than 320GB. However, it would be unwise to base decisions solely on the price, there are so many other factors and features that should be considered when choosing storage like reliability, performance, noise level, warranty period and so on...
  
  
• Speed of rotation in today's hard drives is 7200 RPM (that is rotations per minute). Previous generation offered 5400 RPM and this speed is rare for desktop drives but is common for notebook hard drives. Hard drives with 7200RPM is a good choice today, a faster spinning hard drive can retrieve data faster enhancing overall experience by eliminating delays. Raptors (a special model of Western Digital) are a 10,000 RPM hard drive and are extremely fast, though they are a bit pricey for a regular customer but a must for a performance PC. There are faster server grade hard drives that spin in the excess of 15,000RPM creating noise and heat but do provide the best performance.
  
  
• In general, hard drives tend to be noisy. However, each manufacturer has their own technology to reduce the mechanical sounds. Some brands are quieter than others. Many simply lower the performance, others change the design. When choosing a hard drive look for special notes attributed to reduced noise. A low noise hard drive is worth its extra price for PC users.
  
  
• Many new hard drives offer a bigger cache than yesterday. Older hard drives were offering 2MB-4MB and new generation is offering 16MB-32MB of internal buffer in the hard drive itself. This "buffer" memory is a cache for recently read information and if the file is read sequentially then hard drive can simply send out data from the buffer rather than re-reading it again.
  
  
• Hard Drives come in different sizes fitted for the allowable space in certain applications. The desktop size today is 3.5" and it fits all computers. Notebooks accept 2.5" hard drives. 5.25" was the regular size years ago (size of todays DVD-ROM drives), if you have a 5.25" bay and 3.5" hard drive then you can use special rails "spacers" to fit neatly.
  
  
• With high capacity technologies hard drives use fewer platters (spinning disks inside), thus they require fewer heads and less heads lowers risk of a crash. Research your purchases.
  
  
• About the warranty. The manufacturers have different warranty periods and most will only honor warranties if purchased from an authorized distributor or a registered reseller. We, Directron.com, are an authorized reseller for all hard drive brands that we sell. By the way, Seagate brand offers unheard of 5 year warranty on most of their hard drives. Of course, a warranty can do only so much when important data is lost. That is why the best warranty is to BACK UP!!!
  
  
• RAID can be used either to increase drive performance (RAID 0), improve data integrity (RAID 1), or include both (RAID 10). For RAID you need 2 or more similar drives and a RAID Controller which can either be in the form of a card, integrated motherboard feature, or software (server operating systems). Those looking for extra performance, and those doing large applications such as Database/Server work are encouraged to look into these Redundant Arrays of Independent Disks. RAID controllers exist for SATA, EIDE, SAS & SCSI.
  
  
• The very first use of RAID was to safeguard the data. RAID 1 is known as mirroring method where 2 hard drives have the exactly the same information. If one dies then the other has a complete copy of data nevertheless.
  
  
• Most common among regular users is the RAID 0 for adding performance. You would need 2 drives of the same size (hopefully of the same brand and model) and capability to run RAID 0 on your hardware. "RAID 0" writes a half of data on one drive and another half on the other drive almost doubling the speed of operation. Thus, RAID 0 allows 70%-80% performance increase. The huge problem with RAID 0 setup is that neither drive has even partially complete data. Loss of all data occurs even if one single drive fails. Data on the second hard drive becomes unusable without the complementing data on the failed hard drive. Thus, RAID 0 can be twice as fast but is also be twice as risky.
  
  
• The solution to RAID 0 lack of redundancy problem is to feature a third hard drive that will record byte differences and data can be easily reconstructed with a single drive failure. The described scheme is RAID 10 (aka RAID 1+0 or 0 +1). It requires 4 similar hard drives where two drives are striped together and the other two drives mirror the striped array. This allows for you to swap hard drives if one should fail at any point. This adds a redundancy aspect to a raid 0 setup preventing data loss.
  
  
• Nevertheless, RAID is not a substitute for back-up. Best back-up drive is external that is connected during back-up and kept away from the system any other time. This is done in case of fire, electric, or water damage. In rare cases a system suffers from a power failure that destroys all connected components, even external ones. Therefore, if a back-up drive is kept in the server then it is likely to be a toast too. Moreover, it is best to have 3 methods of back up, RAID 1 or 10 in the server, a separate external backup drive on the network, and a weekly backup stored miles away. While the initial cost of the hardware can be pricey, yet when a disaster strikes you wont have to worry about your data. In addition, having the proper hardware but not actively doing backups makes the hardware useless.
  
  
• Then, if you are REALLY serious about getting fast access to your data, such as large databases and image files, consider using one of the latest hard drive technologies, Serial Attached SCSI (often referred to as "SAS"), which have a typical access time of 3.5- 4.0ms! Wow! That's FAST! But you'll pay for the speed. You also need to use a more expensive SAS controller. Speed of the hard drive may also become a problem if the hard drive is located in the box next to you. These drives spin at very high speeds and are not shy in generating noise.
  
  
• Let us warn you not to buy refurbished hard drives no matter how low the price is. The potential trouble down the road is not worth the savings. That's why Directron.com is staying away from refurbished hard drives as much as possible. Used, but working hard drives are a better and possibly more reliable way to save money. If we do sell a refurbished hard drive then it is clearly marked as such on the product page.