Computer Hardware



	Hardware CPU What To Look For: There is one basic thing to look for in a CPU, the GHz rating. Obviously, the higher, the better. If there is one part you are going to splurge on for your computer, make it the CPU. A good rule to go by is getting a CPU that is a couple steps below the top speed CPU. Bus Speed is another very important thing to look for. Currently 200 MHz is the most common bus speed (although this is often reported as 400 MHz or 800 MHz as it is dual or quad pumped). Internal Cache is the quick access "memory" that is on the CPU to hold recent data. This memory is very important in speeding things up. When comparing CPUs, you may want to look at how much cache the CPU has. Intel's Celeron CPUs have very little cache memory Oddly enough, in some applications it performs quite well, but other applications may cause it to perform very slowly. Another thing to consider with CPUs is the micron size of the CPU die. Smaller sizes result in cooler operation and thus allow for higher clock speeds. The latest CPUs are .13 micron. Buying Tips: So, considering the CPU is the most important part, should you buy the fastest CPU available? Not necessarily. There are two things to consider here. First of all, the highest speed CPU is usually way overpriced. One or two steps down will get you a CPU that will perform just as well to the human eyes, yet cost much less. That is probably the best strategy. A second strategy you may want to consider is to buy a slowish, cheap CPU to start. Purchase the slow CPU with the intention of upgrading your CPU in about a year or less. Then, after that time has passed, you can probably buy a CPU that would be faster than you could have gotten before, but now it would cost much less. CPUs: Buy a 2.6 GHz CPU for $200 when the top of the line is 3.2 GHz for $600. After about a year, buy a 3.4 GHz CPU for about $250. Now, you got a faster CPU, but still saved $150 overall! Note, you might not encounter that wide of a range of CPU speeds that would all fit in the same motherboard. Related topic: Motherboard. CD/DVD-ROM Drive What To Look For: SCSI CD-ROM drives and burners used to be a good choice, but now there are so few available that IDE is the best option. Transfer rates are quite important, but it is not a good idea to just go by the 32X, , 48x, 52x, etc. ratings as they are usually not very accurate. These numbers are supposed to indicate how many times faster the drive is than if it were being played at its default speed (the speed at which you listen to an audio CD). Usually, these numbers only represent the maximum speed these drives can reach. Thus, it is better to compare average sustained transfer rates (not always reported). For CD-ROM burners, it is mainly important to look at the X rating. Look for a burner that writes at 48X or 52X as they are not much more expensive than the older, slower writers (but are a little faster). The law of diminishing returns starts to come into play with these faster drives though, so don't be concerned about the difference between 48x and 52x (it's only going to be a few seconds). The RW (rewrite) speed is how fast it can write to CD-RW discs. This is usually lower than the write speed, and is only important if you plan to use rewritables (which you can write to, erase, then write to again). Look for 24x rewritable speed. The access time is also very important. This is usually measured in milliseconds and an access time of 85 ms is sufficient for a CD-ROM drive. These numbers are usually a lot higher for burners. Like hard drives, the amount of cache is also important. This can range from 64k to 512k, all the way up to 8 MB for CD Burners. 256k is a good number to look for, but 512k is preferred. For CD-ROM burners, look for at least 2 MB of cache as this cache is VERY important in avoiding bad burns (wasted CDs). 2 MB cache buffers should prevent this from happening often. Of course, the higher the better! rpms are also important, but usually are not given. In general, there is not much price difference between the slower and higher speed CD-ROM drives. Anything around 50x is sufficient, and I still think the older 32x drives are sufficient since CD-ROM drives aren't used for large transfers very often. One thing to consider is that the higher speed drives spin faster, which causes them to vibrate and make more noise, and also makes them more prone to failure. It may be a good idea to get a slower speed drive just so that it will last longer and be quieter! Brand can also be important. There are two brands of CD-ROM drive (and burner) that clearly stands out from the rest, and they are Plextor (a pricey brand) and Lite-On (a very inexpensive but surprisingly high quality brand). These drives are much faster and much more reliable than other brands. The X ratings of their drives are also more accurate (a Plextor UltraMAX is rated at 40X, but is actually faster than the so-called "72X" drives). Plextor's drives are superior quality throughout, but they're pricey and harder to find these days. DVD is a next generation media machine to lead the consumer electronics Uses MPEG-2 Compression Technology. Same size as a compact disc Maximizes the recording density of the surface of disc. Holds up to 17Gbyte of data. Capacity of a DVD is 640 MB-7 times the capacity of a CD. DVD uses narrower tracks, and thus more tracks, than a CD. DVD also uses red-laser with short-wave length. Digital Camera What To Look For: Obviously the number of MegaPixels is one of the key items to look for, but anything above 4 isn't even used when printing out small 4x6 or 5x7 prints. The higher MegaPixel cameras allow you to print 8x10 and larger prints without a loss of quality. On the other hand, the newer, higher MegaPixel cameras are more likely to have better picture quality because they are more advanced. Monitor What To Look For: First, consider the monitor size that you want. The larger you can get, the happier you will be. The monitor is the one part that you can keep with you through all the times you upgrade your computer or purchase a new computer, so it doesn't hurt to spend the extra money once on a monitor you will be happy with for awhile. 15" is considered the bare minimum anymore. 17" monitors are also on the small end. The 19" monitors provide a nice large screen at a fairly cheap price, and they don't take up a huge space on your desk either. Anything above 19" is pure luxury and not really needed unless you're into graphic design, etc. If you plan to do graphic design, watch DVDs at your computer, or even play a lot of games then a 21" or larger monitor may be just what you need. The type of monitor is very important in many users' eyes. To me, the "aperture grille" monitors (aka Trinitron or DiamondTron) provide a much superior image to the traditional "shadow mask" monitors, despite having two faint support wires across the screen. Aperture grille monitors are also usually flatter than the shadow mask monitors. The dot pitch of the monitor is one of the most important things to look for when considering a new monitor. It basically shows how clear the picture will be (higher dot pitch numbers may provide a fuzzy image). Anything at .26 mm dot pitch or smaller should be fine for most users. Pay attention to how the dot pitch is measured. It can be written as horizontal, vertical, or other forms. Usually horizontal is used, but avoid or at least question monitors that present different measurements for the dot pitch. Aperture grille monitors often have a dot pitch "range." If that is the case, look for a range of .25-.27 or better (.24-.25). Look for monitors that support fairly high resolutions for their size. Consider, however, that it is impossible for a small 14" monitor to display at 1600x1200 resolution (same for a 15"). 17" monitors are about the minimum to be able to run at 1024x768 comfortably. A 15" monitor can usually do 1024x768, but objects are small and somewhat hard to see. 19" monitors are ideal for running at 1024x768, 1280x1024, or even 1600x1200 (although that's a little too high for my eyes). Higher refresh rates will definitely make computer work easier on your eyes. Consider 75-85 Hz as a minimum refresh rate for any resolution that you actually plan to run your monitor at. Anything above 85 is a nice bonus... Make sure your video card will support the higher refresh rates and resolutions. Another important thing to consider is how flat the monitor is. Watch out though, many manufacturers call their monitors flat, but they are only flat up and down. Sony's "FD Trinitron" monitors are perfectly flat both up and down and side to side. A flat monitor avoids distortion of the image by the curves in the monitor. LCD flat panel monitors are becoming more popular, but not because of better image quality. While they can be brighter, in general the image quality is better on a regular CRT (cathode ray tube) monitor. LCD monitors are really just useful because they take up less desk space. They are also prone to stuck pixels and ghosting of images (since they redraw slowly), thus they are poor for games. The monitor's controls can be important as well. These are helpful in tweaking the picture for proper brightness, contrast, and taking the picture to the very edges of the monitor, not to mention for removing any slight curves or other abnormalities that may be present in the picture. Some monitors come with USB hubs that allow you to easily attach desktop USB items like mice, keyboards, or game controllers without crawling behind your tower case. Front mounted microphones are also often included on the monitors. The speakers that occasionally come on monitors usually have terrible sound, and I would not recommend them. LCD monitor: A monitor is essentially a display panel, just like your television or cell phone screen. And the most advanced display technology on the market is TFTLCD. So the first thing you should decide is which brand of TFTLCD to ask for. Hard Drive What to Look For: First, look at the technology. Do you want IDE or SCSI? SCSI is the faster interface which also takes a load off of your CPU and allows for better multitasking. It also requires the use of a SCSI Card. SCSI is rarely used in home desktop systems, but for the user that wants the best possible performance, SCSI is the way to go. IDE is the more common hard drive interface. It is also a lot less expensive. Over the years, IDE has gotten a lot closer to SCSI in terms of speed too. But, if you are one of those users that wants the fastest possible computer, SCSI is one of the reasons you may want to Build Your Own Computer. If you can afford to go SCSI, you may want to consider a SCSI CD-ROM drive and burner. Other reasons to go SCSI are if you want a lot of devices (you can easily have 15 devices, IDE used to only allow for 4, but newer motherboards come with extra connectors, but still only allow for 2 devices per cable) or you really need the high speed 10,000 - 15,000 RPM drives. Have you decided on IDE? Okay, now do you want traditional IDE (parallel ATA) or the newer Serial ATA? Serial ATA is only possible with newer motherboards that support this connection type. It allows for easier drive connection, theoretically higher speeds, and has much thinner cables. Also the first 10k rpm ATA drive is available only as Serial ATA. Another thing to consider is FireWire (IEEE-1394) hard drives. These are mostly external though. It's a good option for transporting large amounts of data back and forth between multiple computers. The most important numbers to look at in terms of speed are the rpms of the hard drive (revolutions per minute). The faster rpms are going to be much faster hard drives because they spin the discs faster providing faster access to a particular area of the disc. The two most common rpm speeds for IDE drives are 5400 rpm and 7200 rpm (there are some now at 10,000 rpm). I highly recommend 7200 rpm drives over 5400 rpm drives as they provide a big difference in speed. For SCSI, the rpms are usually at 7200 or 10,000, with some newer drives as high as 15,000 rpm. You should also pay attention to the access times. Lower numbers are better here. This is how fast the hard drive can access a particular area of the disc. Next, if you decide to use IDE, look for the Ultra DMA or Ultra ATA rating (both of which mean the same thing and mean that the bus is capable of transferring data at up to a specific rate). What this means is that if you have say 4 IDE hard drives and you only have ATA 33, then the drives would only be able to transfer 33 MB/second altogether. ATA/33 is really all that's necessary because most users only have one or two drives, and the chances of those drives ever being able to transfer more than 33 MB per second is very slim anyway. Having said that, there are currently ATA/100 and ATA/133 standards. Most newer hard drives are ATA/100 or 133, and I would suggest buying an ATA/100 drive at least, not because the drive would ever be capable of transferring data that fast but because it is a "newer" drive and thus is more likely faster than the ATA/66 drives, in general. 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, Ultra-Wide-SCSI, Ultra160-SCSI, and now Ultra320-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 "Ultra320-SCSI" being the highest. Most CD-ROM drives and burners will be "Narrow-SCSI (50 pins), and most current SCSI hard drives are Ultra2Wide, Ultra160, or Ultra320. Next, look at the amount of cache on the drive. Many have only 128kb, 256kb, or 512kb of cache memory. Some SCSI drives have 16 MB of cache or more. I would advise trying to find an IDE drive with at least 2 MB of cache (most now do), and 8 MB cache is getting to be common (and makes a big speed difference). SCSI drives should generally have at least 2 or 4 MB of cache. The previous tips have all focused on speed. Of course, you also want to get a hard drive that will hold enough data. For this, you need to consider the GB size of the drive. Most of today's hard drives start at 40 GBs or larger. 40 GBs is going to be more than plenty for the vast majority of computer users. Power users may want anywhere from 120 to 250 GBs of space depending on their needs (i.e. if you want to store hundreds of CDs in MP3 format, you will want a very large hard drive). Consider 40 GB as a bare minimum size. You won't find many new hard drives smaller than that anyway. Warranty is also important since hard drives are prone to failure. Most IDE hard drives have a 1-3 year warranty, and most SCSI drives have a 5 year warranty. Printer What To Look For: DPI/resolution (DPI stands for dots per inch) is one of the most important numbers to look for. The simplest way to look at this is the higher, the better. Sometimes this is given as two numbers such as 1440x720 dpi or as one number, such as 600 dpi. The 600 dpi number usually means it is 600x600 dpi and the other dpi listing is giving two numbers because it is different by for the horizontal and the vertical dpi. Other things to consider are the cost per print (not always reported by the manufacturers, but very important), the number of pages per minute (the speed), and the actual quality of the printouts, which can usually only be determined by seeing the printer in action. Many electronics stores like Best Buy have printers out where you can print samples, and I suggest you do this to see which looks best on the types of printouts most important to you. Only problem is this isn't necessarily using the highest print quality setting or the proper paper (which makes a huge difference). Also consider the type of printer. Inkjets are inexpensive but provide color printing. Most lasers are greyscale only, but are high print quality. Color lasers are very expensive, but usually have good quality. The less common wax-based printers provide great color image quality, but are also expensive. Sound Cards & Speakers What To Look For: *In Sound Cards* , there are several things you need to look for. One thing to look for is the number and type of input and output connections. If you plan to do professional audio editing, you'll probably need more than just the standard stereo out, headphone out, and microphone in connections. Also look at the number of speakers supported. If you want 3D audio for games, you need support for a 4.1 speaker system. If you plan to watch DVDs, you need support for 5.1, 6.1, or perhaps 7.1 speaker systems (7.1 is the same as 6.1 except that the rear center channel is split into two speakers both carrying the exact same audio). You want to make sure the most recent implementations of 3D audio extensions are supported, such as EAX - Environmental Audio eXtensions). Other things to look for are how many audio simulatneous audio streams are supported, how much memory it has, how many "voices" it supports, whether Dolby Digital 5.1 / EX (6.1) decoding is supported, the recording quality (24 bit, 96 kHz is great), the output quality (24 bit, 192 kHz is great), etc. *In Speakers* , look for brand name reputability. Good brands to consider are Klipsch, Logitech, and Altec-Lansing, not to mention some good sets from VideoLogic and S4 MidiLand. Creative Labs' Cambridge Soundworks speakers are poor speakers for the price. Look for the number of speakers included. 4 speaker sets plus a subwoofer (4.1) are great for gaming. 5.1 speaker sets (adds a center channel) are excellent for listening to DVD movies with and also good for gaming. 2 speaker sets or 2.1 speaker sets are good if you only listen to music and don't want to be surrounded by the audio. Also look for the amount of Watts of power that the speakers are rated at, but this can be very misleading as some companies misrepresent this figure. If it says something over 40 Watts and it's dirt cheap, then it's probably not true. However, many are rated at about 20 Watts, which is quite good. Anything that claims to be higher than 100 Watts is probably junk. Video card What To Look For: There are many different 3D features such as bump mapping, hardware T&L (texture & lighting), Z buffers, FSAA (anti-aliasing - reduces jagged edges), anisotropic filtering (improves detail on textures), etc. The last two are the biggest issues right now. They can dramatically improve the visual quality of games, but always at the expense of speed (which is generally measured in the number of FPS [frames per second]). A low FPS would cause the game to be jerky instead of smooth (and thus more difficult to play). Higher resolutions (i.e. 1280x1024 instead of 640x480) also significantly improve the video quality, but at the expense of speed. It's nice to be able to play games at 1024x768 or higher with 4x FSAA and 4x anisotropic filtering (or better). 4x in the previous number just means the number of passes to render the anti-aliasing and filtering. The more passes, the better the quality. Confused yet? :) AGP or PCI video cards used to be a question, but now pretty much everyone buys AGP video cards. The chipset is what controls the video card's operation and does all the calculations (much like the CPU does for the entire computer). The latest chipsets are designed to do both 2D and 3D applications. The best chipsets currently come from NVIDIA and ATI. Other companies include S3, Matrox, Number 9, etc. The chipset is the most important part of the video card, and the faster, more advanced chipsets will clearly be the better choice. The first decision you should make is which chipset you want to use. This will primarily be dictated by price and the level of performance you're looking for. Video cards have become the most or second most expensive component in a computer (CPUs can cost more). Amount of memory on the card is also important. It can affect the speed of operation as well as the number of colors and resolution size that can be used in games. I would suggest 128 MB for a video card that will be used for gaming. 32 MB is really sufficient for 2D desktop applications though. AGP video cards can also use system memory but that can slow things down, so it's better to have plenty of RAM on your video card. The type of memory is also important. DDR SDRAM is about twice as fast as regular SDRAM, and DDR II is even faster than that (DDR stands for double data rate). Also pay attention to the supported resolutions, refresh rate, and color depth. These are important if you want to run at very high resolutions with a large number of colors. For most home desktop computers, all current video cards will be sufficient in all these aspects. Refresh rate determines how fast the video card can refresh (redraw on the screen) your display. The higher the better. Pay attention to what the max refresh rate are at the higher resolutions. A 60 Hz refresh rate is too low and will cause noticable flicker on your monitor. 85 or 100 Hz is an ideal refresh rate (easier on the eyes), but 75 Hz may be sufficient for you. Make sure your monitor supports these resolutions and refresh rates as well. Some other things to consider are TV-Out, TV-In, video capture capabilities, the speed of the RAM DAC, particular 3D effects that are supported (such as hardware transform and lighting effect), the quality of the cooling fan included (and noise produced by it), and what software bundle the video card comes with since you can often get some good free games through the bundle.