Info & FAQs
Help & Index
Clearance Sale
Community & News
Policies & Feedback
Resources & Support
Discounts & Services
Contact Us
Featured Products
| Home >> Hard Drives & RAID >> Resources - HDD >> |
How To Choose A Computer Power Supply?STILL BEING WRITTEN 1. Introduction 2. Be Safe 3. What wattage do I need? 4. Cheap vs Expensive 5. Types of Connectors 6. Troubleshooting Introduction: Choosing a Power Supply nowadays is not that difficult. The general quality has gone up and the hardest part is to match connectors to what your motherboard requires. Most unusual shape/size cases already are outfitted with a power supply and even a motherboard to match. For all other purposes one would generally want to buy a new PSU (power supply unit) for more power and newer technology, features, stability and dependability. What is a power supply? It is a transformer from AC power to DC power, some energy gets lost and needs to be removed through heatsinks and a fan through air. A good PSU will be 80% to 85% efficient, the others may lose as much power as they convert, making your electric bill higher. The AC (alternating current) is a stream of electrons that are attracted to run towards any ground connection (similar to lightning). On the other hand, the DC (direct current) needs (-) and (+) terminals to create a loop for electrons to move. For high amperage the AC is most efficient way to implement but for electronics and small draw devices (especially those that need "safe" low voltage power) the managed DC is the way to go. To transfer power over long distances from a power plant a very high voltage 100,000+ volts AC is used. When the lines come to your city, then special transformers tame voltage to about 10,000 volts AC and distribute across the streets and to your house another transformer lowers to about 120 volts AC. The power supply takes alternating current and converts it to DC producing heat as a side effect (heat is equal to wasted power). If your power supply is quality built, it can handle sudden spikes, brown-outs, noise on the line (you may get a UPS unit to help fight those). Be Safe: We have to warn you, as with any electric device there is a possibility of an electric shock and even death if the device is not used as it is meant to, not followed safety procedures or if one decides to disassemble the device. Please, keep a power supply unit from moisture, water and never, never disassemble one. The capacitors inside a power supply keep enough voltage to severely shock you even after days from being disconnected from power. The review websites that post pictures with cover removed might give a wrong impression that it is a normal procedure but it is not. Removing a cover from a power supply, opening it in other words, would immediately void warranty and is likely to harm you. Therefore, we urge never try to attempt to repair or give in to curiosity to see what is inside. It is a Pandora box and is not meant to be opened. What wattage do I need? What kind of a computer would the PSU be used in? A regular home PC would not consume more than 400-500Watt. A gaming machine would generally need 600-700 Watt and maybe 850Watt for high end PCs. New monsters of 1000+ Watt are too powerful and yet to find a computer hardware that can utilize all this power. A general modern computer consumes around 120-180 Watts at idle but through out the utilization the power requirements peak to 300+ Watts. The power supply's maximum wattage must be sufficient enough to supply enough power during these peaks even if they last for a microsecond. For example, when a computer starts up then all its components come to life at the same time and consume a lot of energy during that state, all the devices become suddenly powered and some require even extra power to build momentum. During idling the computer is likely to put most unneeded devices to sleep but during gaming the high draw devices need most power. Today the hungriest device is a video card. During the 3D mode a video card requires more power and now with Vista even displays the desktop in 3D mode (unlike in XP). If you are running multiple video cards in SLI or CrossFire then you have two hungry beasts. Modern GPUs consume more power than ever before requiring more powerful PSUs. The CPUs themselves now have a trend to become more efficient and less power hungry as a generation ago. AMD and Intel have worked hard producing new CPUs that run cooler and require only 30-40 Watts at their maximum peak. Add one of these CPUs with a video card that is on-board and you have a computer that is very moderate with power consumption. However, latest quadcores do consume a lot of power, QX6850 can draw up to 130Watt of power, that is twice as much as your regular incandescent light bulb. Also, each additional component requires power, if you have a PCI video card, full slots of RAM, it all needs power, not as much as video cards but still they need to be powered up. Plus, if you are running multiple fans to cool your case, you might think of getting more power. So, you cannot hurt your system by getting more powerful PSU (think of it that it will be ready for upgrades), however, if you under power your system, you may experience all kinds of random and unexplained crashes when the components will be starved. Yet, keep in mind that a PSU of a higher wattage will cost more to operate because it might have better efficiency only when you draw about 80% of its operational capacity and if you are below, the PSU will waste some power in vain. Cheap vs Expensive: How much one generally should spend on a power supply? The answer depends on what kind of a computer you have or building. More watts cause the hardware to be more intricate and thus the cost. Some cheaper PSU makers may state higher wattage which is generally never can be achieved. Therefore, capabilities of a cheap PSU vs a premium brand are not the same even if they state the same wattage. For a general home system a PSU priced $50-$80 should be quite enough. For a business machine a PSU priced around $100 would give you dependability. For a gaming system a power supply we advise to spend $120-$180 for a quality unit. Higher priced power supplies are a personal caprice. Types of Connectors: Following connectors will be discussed for ATX form factor. Connection to a motherboard: CPU Power connector - This connector appeared when CPUs required direct power that was not shared with the rest of a motherboard device set. A 4-pin connector appeared that hooks up in the vicinity of a CPU to the motherboard and goes through several stages to clean the power for CPU consumption. Now with new CPUs you can see 8-pin connectors. Extra 4 pins is a duplication of existing pins, probably built in to support motherboards with 2 CPUs in the future. Motherboard Power Connector - This connector is an assembly of different cables that communicate and send power to the motherboard. This connector is 20 or 24 pin. Extra 4 pins was added to the standard not long ago and is really just extra duplicated cables. One can buy an adapter that would allow to convert 20-pins to 24-pins. Connection to devices: Troubleshooting: Aside from other problems that your computer may experience, a power supply is one of the most frequent problems exhibiting itself by not booting your computer. Choose any of the symptoms: Your computer will not spin CPU fan, nothing works: 1) Is the remote power on cable attached properly to the motherboard, check that it is in fact power on and not to reset switch cable. 2) Is the power on switch operational? You can simply for a second short the power-on pins with a jumper, don't leave it on and make sure you are jumping correct pins or you may short and burn your motherboard. 3) Check pin map on motherboard by reading a manual that came with the motherboard, some mother boards may require a 3 pin instead of a 2 pin your case may have. 4) 5) 6) 7) 8) |
Customer Feedback through Yahoo!
Related Sections
| Microsoft Natural Ergonomic Keyboard 4000 wired Keyboard, Mod... Only $19.99 | |
| WD Caviar Green 3.5in 1TB SATA 3.0Gb/s Internal Hard Drive, 7... Only $78.99 | |
| Cooler Master Sentinel Advance Gaming Mouse SGM-6000-KLLW1-GP... Only $45.99 | |
| Black ASUS USB Optical Mouse mini-N6 and USB Keyboard 820-001... Only $5.99 | |
| A-DATA Turbo 4GB microSDHC Class 6 Flash Card, P/N: AUSDH4GCL... Only $5.99 | |
| Sabrent All in 1 USB 2.0 External Flash Memory Mini Multi Car... Only $2.99 | |
| Black MSI U100-641US 10-inch Wide Wind Netbook, Intel Atom N2... Only $249.99 | |
| Syba Combination Laptop Security Lock, Model: SY-NBK65004... Only $3.99 | |
| *$5 Mail-In Rebate* Black/Blue OCZ Equalizer USB Laser Gaming... Only $9.99 | |
| eMachines EL1300G-02W Slim Line Desktop System, 20in Widescre... Only $329.99 | |
| *$5 Mail-In Rebate* Copper CoolMax 2.5in Aluminum SATA HDD En... Only $6.99 | |
| Acer AspireRevo 1600 AR1600-U910H Desktop PC PT.SCL05.004, In... Only $199.99 | |
| *$15 Mail-In Rebate* Thermaltake BlacX HDD Docking Station ST... Only $34.99 | |
| Sabrent High Resolution 1680x1050 TV Tuner Box with Picture i... Only $29.99 | |
| Memorex 16X 4.7GB DVD-R Blank Media, 50-Pack Spindle, P/N: 32... Only $8.99 | |
| TP-Link 54M Wireless Router TL-WR340G, IEEE 802.11g/b, w/ 4-P... Only $14.99 | |
| Kinamax USB 2.0 Webcam Camera WCM-6LNV, 6-LED Infrared Night... Only $9.99 | |
| *$15 Mail-In Rebate* Thermaltake Massive23 ST Notebook/Laptop... Only $29.99 | |
| Black Shuttle Black XPC Barebone System SN78SH7, nVidia GeFor... Only $199.99 | |
| Cooler Master Silent Pro M 850W ATX12V / EPS12V Computer Powe... Only $114.99 | |
| Black Cooler Master Storm Scout ATX Mid Tower Computer Case S... Only $68.99 | |
| Cooler Master V8 CPU Cooler RR-UV8-XBU1-GP, for Intel Core i7... Only $37.99 | |
| Black Cooler Master Notepal X2 Notebook Cooler, Up to 17in No... Only $15.99 | |
| Kingston HyperX 4GB(2x2GB) DDR3 Dual Channel Kit Memory KHX20... Only $94.99 | |
| Pink MSI Wind U100-427US 10in WSVGA Netbook 9S7-N01153-427, I... Only $249.99 | |
| Silver Blue MSI Wind U100-013US 10in WSVGA Netbook 9S7-N01158... Only $249.99 | |
| Black Broadway Com Corp Sonic SECC Steel ATX Mid Tower Comput... Only $19.99 | |
| PNY Optima 2GB DDR2 667 (PC2-5300) System Memory, 240-pin DIM... Only $33.99 | |
| Holiday Combo Deal 2: ASUS P5G41-M-LE/CSM Motherboard with In... Only $99.99 | |
| *$20 Mail-In Rebate* Kingston SSDNow V Series 64GB 2.5in SATA... Only $109.99 |