2. Fibromialgia
2.3 Modelos animales para estudiar la fibromialgia
As everything you have on the PC at some point needs the motherboard, you need to consider these components when buying a motherboard. For example, if you have a lot of devices with a PCI interface that you wish to use, there is little point buying a motherboard that only offers you 3 PCI slots. Like wise with memory, you have to make sure that there are enough slots for the amount of memory you have or wish to have.
The motherboard also needs the correct type of interface for your Memory, Graphics card, Hard disks and other items as well. You will find that most motherboards offer everything you need however it needs checking on when buying. Its especially important to pay detail to your motherboard if you want to use older components, which a new motherboard may or may not support.
The major difference between motherboards that support the same CPU is the model of the chipset (more on the chipset later). Different chipsets offer different performance and different features in terms of memory support, AGP port speed, Multiplier numbers, Bus speeds and much more.
When you are choosing one motherboard you have to consider:
What's Your Processor?
First and most important thing to consider when buying your motherboard - what CPU or processor are you using? Motherboards are made differently, not all motherboards will support all CPUs.
What CPU you select will determine the type of motherboard you get. For example, if you want to use an Intel Pentium 4 CPU, the motherboard you select must be able to support that brand and model of CPU.
The motherboards are also designed to support specific speeds for a CPU, so make sure it can support the speed of the processor as well.
Choose Your Chipset
What is a chipset? Well, chipsets are the main controllers on the motherboard - they allow the CPU to interface with the various components and expansion cards installed.
When choosing your chipset, always bear in mind the type of memory supported by the motherboard. Make sure that the board supports the type and amount of RAM you need. Generally, choosing a chipset that supports high speed memory will allow your system to perform better.
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What is a Motherboard Chipset?
A motherboard chipset controls all the data that flows through the data channels (buses) of the motherboard. The primary function of the motherboard chipset is to direct this data to the correct area's of the motherboard, and therefore the correct components.
Expansions Slots and Connectors
If you intend to various peripherals to the computer, then the number and type of expansion slots and connectors is important. By default, most motherboards these days have USB 2.0 ports incorporated into their design.
If you intend to buy expansion cards, make sure the board comes with an ample number of PCI slots.
Other Features
These days, most motherboards have a whole host of extra features loaded into them. These can include things such as on-board VGA, audio, a RAID controller, Modem or Network Card.
CHAPTER 4: RAM
RAM (Random Access Memory) is the basic working memory of your computer system. A computer used RAM to hold volatile (Temporary) instructions and data needed for processing. Volatile simply means that it is not permanent, which means anything written to RAM will be loses if the machine loses power or if it's turned off.
Another key point about RAM is that data stored init can be accessed much more quickly than data retrieved from the hard disk. Theoretically data retrieved from RAM is accessed 100 to 300 times faster then the same information from a hard disk, optical drive, or a floppy.
Memory is measured in bytes, so you'll often encounter the terms megabyte (MB) and gigabyte (GB) in describing RAM sizes (a megabyte is a million bytes; a gigabyte, a billion). RAM is something that you do not want to skimp on. You can choose a slower processor, but with RAM you want as much as you can get.
Types of RAM:
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SDRAM
Almost all systems used to ship with 3.3 volt, 168-pin SDRAM DIMMs. SDRAM is not an extension of older EDO DRAM but a new type of DRAM altogether. SDRAM started out running at 66 MHz, while older fast page mode DRAM and EDO max out at 50 MHz. SDRAM is able to scale to 133 MHz (PC133) officially, and unofficially up to 180MHz or higher. As processors get faster, new generations of memory such as DDR and RDRAM are required to get proper performance.
DDR Memory (184-pin DIMMS)
These were introduced in 2002 to replace the earlier SDRAM format. To use this type of memory you need a 184-pin socket for the module to fit into.
DDR Memory is available in different speeds of PC2100, PC2700, PC3200 (DDR400), and PC4000 (DDR500). The modules can be used singly or how desired however you cannot mix different speeds together.
DDR2 Memory (240-pin DIMMS).
This format builds on the technology of DDR . This standard has more pins and its main developments are the ability to run faster whilst consuming less power.
To use DDR2 memory you need a 240-pin socket for the module to slot on your motherboard. DDR2 Memory is available in many different speeds including PC2-3200 (DDR2400), 4200 (DDR2533), and PC2-5300 (DDR-667).
The modules can be used singly or you can install different speeds of DDR2 memory together if your motherboard supports the faster speed however faster modules will perform at the lower speed.
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This may be worth considering if you want to run Dual-Channel memory where you must use the same speed and ideally matching pairs to ensure compatibility.
DDR3 Memory (240-pins)
THIS is the latest memory standard (2008 onwards) taking over from the previous DDR and DDR2 standards. Although DDR3 comes with 240-pins the same as DDR2 the notch is in a different place so people can not install the wrong type.
DDR3 is not backward compatible with DDR2 in addition to the notch the voltage runs at a lower 1.5V than DDR2 1.8V. DDR3 memory will not fit into a standard DDR2 DIMM socket or an earlier DDR memory socket.
To use DDR3 memory, your system motherboard must have 240-pin DIMM slots and a DDR3-enabled chipset.
CHAPTER 5: HARDDISK
The hard disk (or hard drive) is the permanent storage area of your computer. It stores information whether the computer is on or off. A hard drive is a mass storage device found in all PCs (with some exclusions) that is used to store permanent data such as the operating system, programs and user files.
The data on hard drives can be erased and/or overwritten, the hard drive is classed as a non-volatile storage device which means it doesn't require a constant power supply in order to retain the information stored on it (unlike RAM).
Inside every hard drive are small round disk-like objects made of either an aluminum/alloy or a glass/ceramic composite, these are called platters, each platter is coated with a special magnetic coating enabling them to store data magnetically. Hovering above these platters are read/write heads that transfer data to and from the platters.
Hard drives come with many different storage capacities, hard drive capacity is measured in bytes, with common capacities being stated in MB (Megabytes) and GB (Gigabytes).
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Hard Drive RPM Speeds
You will often see hard drives advertised as being capable of a certain RPM (Revolutions Per Minute), this figure (as the name suggests) refers to how many times the spindle makes a complete 360? turn in any single minute. RPM values range from about 5,400RPM to 12,000RPM and above.
How to Choose a Hard Drive
When you are choosi ng one Hard Drive you have to consider:
ATA and SCSI
In the hard drive world, there are two data access standards, ATA and SCSI (pronounced 'Scar-Zee'). Most of normal hard drives we're used to rely on the PATA standard. Some newer hard drives use the SATA standard.
SATA allows transfer speeds of up to 150 MBs while PATA gives up to 133 MBs.
However, to use SATA, you'll need a Serial ATA controller, a SATA drive and a SATA power cable. The speed difference between PATA and SATA is also not significant unless you have a high-end SATA drive.
The SCSI standard is a very fast hard drive standard used for professional computer systems which demand extremely fast data access. SCSI drives provide an access time of about 9.5ms - which I feel is really not needed for average home use.
Disk Space vs. Price
An important factor to consider is the disk space versus price ratio. When you look at the 30 GB, 40 GB and 80 GBPATA hard drives, you'll find they are very close in price. For the average home user, however, 40 GB to 80 GB of disk space is plenty.
Drive Speed
If data access speed is important to you, you can go for faster SATA drives or SCSI drives. But remember that these drives come at a price premium and may not be necessary for average home use.
CHAPTER 6: CARD
6.1: Video Card
VGA Card is the one sending the monitor signal to the monitor.
A computer video card is placed in the motherboard, where it transfers video signals through a cable to your monitor. The video card can either be built into
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the motherboard or be a separate card that is placed in either the AGP or PCI-Express Slot.
The computer graphics cards major job in a computer is to convert graphic patterns into signals for the monitor's screen. However in recent times as the graphics card
has become more
advanced it has taken some of the jobs previously assigned with the CPU and through a graphics pipeline adds 2D and 3D effects and it also adds textures.
How to Choose a Video Card
The VGA Card price will change on 1. VGA Card Processor
2. VGA Card Ram capacity 3. Ram type of VGA Card
When you are choosing one Video Card you have to consider:
The best way to see what video card to buy is to consider how you're using your computer now. There are several categories:
Server
If you're using your computer as a mail server, FTP server, print server, or even a game server, you definitely do not need a high-end video card. What you need is a simple, no-frills low-end video card.
Simple Applications
Say you're using the PC for simple applications only, for example, word processing, email or web surfing. Again, you do not need the best video card out there. A cheap and decent one will do the trick.
Complex Applications
If you need to perform more complex tasks like 3D computer aided design or video editing, it will make more sense to go for a heavy duty card. Screen
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resolution and image quality tend to be important factors for this type of work.
Look for a video card whose processor which supports a high screen resolution, with ample graphics memory.
General Games
If you'll only play simple games like Minesweeper, Reverse or Backgammon, then my advice is to save your money and just get a simple video card. No need for the latest 3D graphics gizmo.
6.2: Sound Card Sound Card
The sound card is an essential component in the PC, since it translates digital signals into analog audio for your listening pleasure. Well, that's true, if you want to play games or run multimedia applications in your PC.
Otherwise, it may not be necessary, especially in business environments.
Sound card ports
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A computer sound card is used by a computer for music, sounds during applications and entertainment (TV, movies and games). A typical sound card usually has four ports. The largest port is the Midi/Game port , which is used for connecting a joystick or gaming controller to. The other three ports look similar and are generally green, pink and blue.
Underneath each port will be a small engraving of what each port does. The pink port is for a microphone which can record sound to the computer. The green port is line out and this is where the speakers are connected to produce sound from the computer. The blue port is line in and this is for connecting a CD-player or cassette tape to the computer.
Remember a sound card by itself is not enough to hear sound. You will still need to purchase some computer speakers or a headphone set. If you want to make use of the microphone feature then you will need to buy a computer microphone and you should then be able to record sound to your computer.
How to Choose a Sound Card
When you are choosi ng one Sound Card you have to consider:
First thing to consider here is your intended usage of the sound card. If all you want is basic sound support and not spectacular 3D surround sound, I'd say go buy a cheap, simple card or even rely on your motherboard's on-board sound.
If you want great surround sound and better speaker connectivity options, then you'll want to consider a dedicated sound card.
6.3: Modem Card
A device that translates data from your PC into a form that can be sent to other computers over regular phone lines. The modem also receives signals from other
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computers and converts it into something your computer can understand. A modem is the device most home computers use to connect to the Internet.
A Modem converts digital information into sound so that it may be transmitted over telephone lines. When the modem hears this sound on the other end it converts the sound back into digital information.
There are two types of modems:
• INTERNAL
• EXTERNAL
External modems are slightly more expensive than internal modems and are housed in an external box or enclosure. External modems require a socket on the computer or port (usually the serial port on the back of your computer.) The serial port is also called a COM port, com for communications.
6.4: Network Card
A network interface card , more
commonly referred to as a NIC, is a device that allows computers to be joined together in a LAN, or local area network. Networked computers communicate with each other using a given protocol or agreed-upon language for transmitting data packets between the different machines, known as nodes . The network interface card acts as the liaison for the machine to both send and receive data on the LAN.
The most common language or protocol for LANs is Ethernet, sometimes referred to as IEEE 802.3. A lesser-used protocol is Token Ring. When building a LAN, a network interface card must be installed in each computer on the network and all NICs in the network must be of the same architecture. For example, all must either be Ethernet cards, Token Ring cards, or an alternate technology.
An Ethernet network interface card is installed in an available slot inside the computer. The NIC assigns a unique address called a MAC (media access control) to the machine. The MACs on the network are used to direct traffic between the
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A network interface card does not have to be hard wired with physical cable.
Wireless Ethernet cards are installed like their wired counterparts, but rather than a port for an Ethernet cable, the card features a small antenna. The card communicates with the central wireless switch or hub via radio waves. Wireless LANs may have some restrictions depending on the material the building is made from. For example, lead in walls can block signals between the network interface card and hub or switch.
When buying components for a LAN, make sure the NICs and hub or switch have the same capabilities. The entire network must be either wired or wireless, so a wireless network interface card cannot talk to a wired switch or hub. In addition, newer versions of hardware will likely support more features and/or greater speeds than older versions. Make sure your central switch or hub can utilize the highest capabilities of the network interface card under consideration.