![[H]ard|Forum](/styles/hardforum/xenforo/logo_dark.png){kind=logo}
Here's a 3-minute power supply faq for those who are new to this kind of thing:
Why should I care about what power supply I have?
An underpowered or low-quality power supply can lead to system instability and may damage your components. It may also limit the overclockability of your system. In some cases, poor-quality power supplies have been known to pose a fire hazard and may present a risk to your computer or worse.
What do I need in a power supply?
You want to purchase a power supply that puts out enough wattage at the proper voltages to power all of the components in your system. You will want a power supply that will put out stable voltages, even under load, without voltage drop, ripple, spikes, or other electrical problems. You may also want to consider the noise that a power supply produces, as well as the thermal impact it will have on your system. Also look to see if the power supply has ATX12V (often called "P4 support"), and if it has SATA connectors. You may need these now or later.
How many watts do I need?
That's a complex question. You're better off buying a 300 watt quality power supply than a "400 watt" power supply that's a piece of garbage. Moreover, even a "500 watt" power supply may not deliver enough power at the proper voltages.
Here's a simple guide, assuming your're buying a quality power supply with decent rails:
Simple System:
- P4 (Northwood) / Athlon XP / Sempron / Athlon 64 / Celeron
- Not Prescott
- Onboard graphics
- 1-2 hard drives & 1-2 optical drives
250W minimum, 300W recommended
Light Gamer System:
- P4 (Northwood) / Athlon XP / Sempron / Athlon 64 / Celeron
- Not Prescott
- Mainstream graphics card (anything without a power connector)
- 1-2 hard drives & 1-2 optical drives
300W minimum, 350W recommended
Moderate Gamer System:
- Any CPU
- High-end graphics card (Radeon 9800/X800XT, GeForce 5900, or GeForce 6800)
- Not GeForce 6800GT or Ultra
- 1-2 hard drives & 1-2 optical drives
350W minimum, 400W recommended
Ultra Gaming System:
- Any CPU
- Any graphics card
- 1-4 hard drives & 1-4 optical drives
450W minimum, 500W recommended
Ultra-High Power:
Any of the following:
- Multiple CPUs
- 5+ ATA/SATA hard drives
- 3+ SCSI HDDs or Raptor HDDs
- Dual GPUs
550W minimum, may be more depending on configuration
Why are your power requirements so high?
While you can certainly run a P4 Prescott system on 250W, or perhaps even 200W, it requires that the power supply perform precicely to it's specifications and that it's designed to do so. Most power supplies aren't this good, and it's unwise to run even the best power supplies at their max. The figures supplied have enough "slop" to allow for variances in power supplies and to allow for a safety margin. Remember, a poor-quality power supply can cause headaches even if it's not anywhere near it's "rated" capacity.
What about power supplies with cases?
With a few exceptions (Antec, most small-form-factor systems), they are of poor or at least unknown quality. It's simply not worth it to burn out your $100 motherboard because you didn't buy a quality power supply.
What about OEM systems?
If you're upgrading an OEM system (Dell, HP), keep in mind that they almost universally have underpowered supplies. Many HP computers have a 180W power supply or less. Remember to check the rated wattage. If in doubt, contact the manufacturer. Remember, adding parts to an OEM system often voids the warranty.
Can I mod my PSU?
Yes, but unless you really know what you're doing you're likely to damage the power supply, your computer or both.
And now the all-caps warnings:
DO NOT OPEN YOUR POWER SUPPLY UNLESS YOU KNOW WHAT YOU ARE DOING. IF YOU ARE UNSURE, DO NOT OPEN YOUR POWER SUPPLY.
POWER SUPPLIES CONTAIN HIGH VOLTAGES, EVEN AFTER THEY ARE DISCONNECTED FROM THE WALL. ALWAYS ALLOW A POWER SUPPLY TO DISCHARGE FOR SEVERAL HOURS BEFORE OPENING IT. ALWAYS EXCERSIZE CARE WHEN WORKING INSIDE A POWER SUPPLY.
OPENING YOUR POWER SUPPLY MAY VOID YOUR WARRANTY.
What brands are good?
Antec, Fortron, Sparkle, PC Power and Cooling, Zalman, Vantec, Seasonic, and Enermax are generally considered to be quality brands. Remember, there may be exceptions. Read reviews and ask for advice here before you buy. You can always buy a PSU off this list.
Can you recommend a PSU?
Look at this list.
Why should I care about what power supply I have?
An underpowered or low-quality power supply can lead to system instability and may damage your components. It may also limit the overclockability of your system. In some cases, poor-quality power supplies have been known to pose a fire hazard and may present a risk to your computer or worse.
What do I need in a power supply?
You want to purchase a power supply that puts out enough wattage at the proper voltages to power all of the components in your system. You will want a power supply that will put out stable voltages, even under load, without voltage drop, ripple, spikes, or other electrical problems. You may also want to consider the noise that a power supply produces, as well as the thermal impact it will have on your system. Also look to see if the power supply has ATX12V (often called "P4 support"), and if it has SATA connectors. You may need these now or later.
How many watts do I need?
That's a complex question. You're better off buying a 300 watt quality power supply than a "400 watt" power supply that's a piece of garbage. Moreover, even a "500 watt" power supply may not deliver enough power at the proper voltages.
Here's a simple guide, assuming your're buying a quality power supply with decent rails:
Simple System:
- P4 (Northwood) / Athlon XP / Sempron / Athlon 64 / Celeron
- Not Prescott
- Onboard graphics
- 1-2 hard drives & 1-2 optical drives
250W minimum, 300W recommended
Light Gamer System:
- P4 (Northwood) / Athlon XP / Sempron / Athlon 64 / Celeron
- Not Prescott
- Mainstream graphics card (anything without a power connector)
- 1-2 hard drives & 1-2 optical drives
300W minimum, 350W recommended
Moderate Gamer System:
- Any CPU
- High-end graphics card (Radeon 9800/X800XT, GeForce 5900, or GeForce 6800)
- Not GeForce 6800GT or Ultra
- 1-2 hard drives & 1-2 optical drives
350W minimum, 400W recommended
Ultra Gaming System:
- Any CPU
- Any graphics card
- 1-4 hard drives & 1-4 optical drives
450W minimum, 500W recommended
Ultra-High Power:
Any of the following:
- Multiple CPUs
- 5+ ATA/SATA hard drives
- 3+ SCSI HDDs or Raptor HDDs
- Dual GPUs
550W minimum, may be more depending on configuration
Why are your power requirements so high?
While you can certainly run a P4 Prescott system on 250W, or perhaps even 200W, it requires that the power supply perform precicely to it's specifications and that it's designed to do so. Most power supplies aren't this good, and it's unwise to run even the best power supplies at their max. The figures supplied have enough "slop" to allow for variances in power supplies and to allow for a safety margin. Remember, a poor-quality power supply can cause headaches even if it's not anywhere near it's "rated" capacity.
What about power supplies with cases?
With a few exceptions (Antec, most small-form-factor systems), they are of poor or at least unknown quality. It's simply not worth it to burn out your $100 motherboard because you didn't buy a quality power supply.
What about OEM systems?
If you're upgrading an OEM system (Dell, HP), keep in mind that they almost universally have underpowered supplies. Many HP computers have a 180W power supply or less. Remember to check the rated wattage. If in doubt, contact the manufacturer. Remember, adding parts to an OEM system often voids the warranty.
Can I mod my PSU?
Yes, but unless you really know what you're doing you're likely to damage the power supply, your computer or both.
And now the all-caps warnings:
DO NOT OPEN YOUR POWER SUPPLY UNLESS YOU KNOW WHAT YOU ARE DOING. IF YOU ARE UNSURE, DO NOT OPEN YOUR POWER SUPPLY.
POWER SUPPLIES CONTAIN HIGH VOLTAGES, EVEN AFTER THEY ARE DISCONNECTED FROM THE WALL. ALWAYS ALLOW A POWER SUPPLY TO DISCHARGE FOR SEVERAL HOURS BEFORE OPENING IT. ALWAYS EXCERSIZE CARE WHEN WORKING INSIDE A POWER SUPPLY.
OPENING YOUR POWER SUPPLY MAY VOID YOUR WARRANTY.
What brands are good?
Antec, Fortron, Sparkle, PC Power and Cooling, Zalman, Vantec, Seasonic, and Enermax are generally considered to be quality brands. Remember, there may be exceptions. Read reviews and ask for advice here before you buy. You can always buy a PSU off this list.
Can you recommend a PSU?
Look at this list.
