2. One good way of determining a bad power supply is that the fan will not rotate. Also, the computer will not boot and the LED s indicating the power and disk activity will be OFF.
3. ATX12V 2.0 power supply provides four different voltages:
4. 3.3Volts, 5Volts, 12Volts and -12Volts. Previous versions of ATX12V used to provide -5V, and it has been discontinued in version 2.x.
5. ATX style systems use two power connectors, P8 and P9 to connect to the motherboard. ATX systems use only one P1 connector to connect to the motherboard.
6. Uninterrupted Power Supply (UPS)
a. An UPS is required for any critical and un-interrupted use of computers. It has the following benefits:
1. Provide protection against small surges
2. Filters noise from entering the computer
3. Provide power to the computer during line power failure
4. Give stable power to computer, even when the line power is unstable.
b. Note that the UPS can give un-interrupted power only for a fixed amount of time under a given load, in the absence of line voltage
7. Some PCI Express Graphics cards require extra power. High-end graphics cards will consume from 75 watts up to 150 watts of power. The PCI Express x16 connector can deliver up to 75 watts. In order to achieve 75W, an ATX12V power supply with a 2x12 main power connector is recommended. 25W-75W graphics cards are powered through the desktop board's PCI Express x16 connector. For additional power requirement, a new connector on the graphics card has been designed to supply up to 150 watts. This means an entirely new power supply will be required for some new graphics cards.
8. When selecting a power supply, two issues become important. You need to supply the total wattage required by all the devices and the motherboard of the PC, and you must ensure that it has the connector types required by your devices.
9. SATA: The SATA power connector is 15 pins, with 3 pins designated for 3.3 V, 5 V, and 12 V, with each pin carrying 1.5 amps. This results in a total draw of 4.95 watts + 7.5 watts + 18 watts, or about 30 watts.
10. A Molex connector is used to provide power to drives of various types. It has four pins, two of which have power, one 12 V and the other 5 V. These are standard for IDE (PATA) or older SCSI drives. The total power demands are from 5 to 15 watts for IDE and 10 to 40 watts for SCSI.
4/8-pin 12 V: With the introduction of the Pentium 4, the motherboard required more power. Supplemental power connections were provided to the motherboard in 4-, 6- (discussed later in this section), or 8-pin formats. These were in addition to the 20-pin connector (discussed later in this section) that was already provided.
11. There is a 4-pin square mini version of the ATX connector, which supplies 2 pins with 12 V, and an 8-pin version (two rows) that has four 12 V leads. These connect to other items, like the processor, or other components, like a network card that may need power that exceeds what can be provided with the ATX connection to the board.
12. PCIe 6/8-pin: PCIe slots also draw more power and require power in addition to the main 20-pin connector (discussed next). These additional connectors can be 6 pins and may also contain an additional 2-pin connector on the side for cases where the connection required is 8-pin.
13. 20-pin: The main ATX connector, referenced earlier, is a 20-pin connector. The four pins carrying power are 3.3 V, 3.3 V, 5 V, and 5 V. This allows the motherboard to pull about 20 to 30 watts.
14. 24-pin: The 24-pin ATX connector is simply the 20-pin connector discussed earlier along with the extra 4-pin connector on the side. This provides the 4 pins carrying power as discussed earlier plus an additional 4 pins with 5 V standby, 12 V, 12 V, and 3.3 V.
1. 32-bit Operating systems (especially, workstation Operating Systems such as XP) usually support only up to 4GB of memory due to address bus limitation. It is recommended to go for 64-bit operating system if you want to use more than 4 GB of memory.
2. SLI technology is designed for PCI Express and not AGP. This new bus has superior bandwidth (two to four times AGP 8X), support for isochronous data transport, and the capability to drive multiple high-speed graphics devices like running video games.
3. Computers used for graphic design, computer-aided design (CAD) applications, and computer-aided manufacturing (CAM) require much more horsepower than the standard PC. Specifically, they require multiple or more powerful processors, more robust video cards, and significantly more memory.
4. SATA hard disks may be used for building RAID arrays.
5. Dynamic disks are not supported in portable computers and on external USB devices. The primary reason being that dynamic disks are used for enabling RAID configuration or back configuration, which requires two or more disks to be present. Usually, portable computers and USB hard disk drives come with single hard drive.
6. RAID Level 10 requires a minimum of 4 drives to implement. RAID 10 is implemented as a striped array whose segments are RAID 1 arrays. RAID 10 has the same fault tolerance as RAID level 1. If a disk fails replace the failed disk and see if the RAID builds up. For single disk failures, usually, RAID 10 heals itself.
7. The hardware on the machine must have enough memory, hard drive space, and processor capability to support the virtualization. You also need the software to make virtualization possible.
8. Home Server
a. A home server is a server located in a private residence providing services to other devices inside and/or outside the household through a home network and/or the Internet. Such services may include file and/or printer serving, video/audio serving, web serving (on the network or internet), web caching, account authentication and backup services.
b. Windows Home Server is based on Windows Server 2003 R2 and is intended to be a solution for homes with multiple connected PCs to offer file sharing, automated backups, print server, and remote access.
c. Important features of a Home Server are given below:
1. Centralized backup: Backup individual computers at a central location.
2. Health monitoring - Monitor health of individual computers
3. File sharing - Enables file sharing over the home network
4. Printer sharing - Enables printer sharing over the network
5. Remote access gateway - Allows remote access to any connected PC on the network, including the server itself, over the Internet.
6. Media streaming - Can stream media to an Xbox 360 or other devices supporting Windows Media Connect.
7. Selective data redundancy - Guards against a single drive failure by duplicating selected data across multiple drives.
8. Expandable storage - Provides a unified single and easily expandable storage space, removing the need for drive letters.
9. Server backup - Backs up files which are stored within shared folders on the server to an external hard drive.
d. When combining various servers into a single physical box, it is important to consider the server hardware requirements, such as CPU, Memory, Power Supply, Expansion Slots, Hard Disk Capacity, etc.
9. StickyKeys is designed for people who have difficulty holding down two or more keys at a time. When a shortcut requires a key combination such as Ctrl+P, StickyKeys allows you to press one key at a time instead of pressing them simultaneously.
10. Character Map: You can use Character Map to copy and paste special characters into your documents, such as the trademark symbol, special mathematical characters, or a character from the character set of another language.
11. Pointer trails can help people who struggle to track the movement of the pointer on both modern TFT screens and traditional 'tube' CRT screens.
12. A screen magnifier is software that interfaces with a computer's graphical output to present enlarged screen content.
13. When discussing thin and thick clients, you should understand that a thick client is a PC that has all the capabilities of a standard PC. It runs all applications locally from its own hard drive. A thin client is one that has minimal capabilities and runs the from a remote server
14. Wake-On-Lan requires a few settings as below:
a. An ATX motherboard with an onboard, 3-pin "WOL" connector and ATX power supply.
b. A network card that can support WOL with its cable to the motherboard properly installed.
c. In the BIOS Power Management, you must enable the LAN Wakeup option.
d. Then take a look at your network card settings, (right click mouse on "My Computer" icon on your desktop, select Manage -> "Device Manager") in "Device Manager" open properties of your "Network Card" and select "Power Management" tab. You need to check appropriate boxes enabling the Network Card to bring the computer out of standby.