The Power Supply Unit

Sometimes power supplies come with a computer case you buy. It is my personal opinion that you should just trash it and get a good power supply! The very last think you want to happen after you’ve build your new computer is for it to be fried by a cheap power supply.

Make sure the power supply you use is of high quality and is adequate for your needs and has the correct connectors for the type of system you are building.

It’s also important to select a power supply that can provide sufficient wattage for your system and that has the right connectors. Take a look at your video cards power supply recommendation. I always like to take that an add 100watts. So if the video card you are installing requires a 550w power supply get a 650w power supply. That should be sufficient for most processors, your video card, one hard drive and one optical drive. If you intend to add more hard drives and optical drives add about 25w for each extra device.

Most power supplies today come with lots of SATA connectors, but few Molex connectors. If you’re using drives or cards that need Molex but don’t have enough Molex leads (or vice-versa) you’ll either have to make sure the power supply has enough of what you need, or else buy some adapters.

In every product description of the parts you buy, you will be told what connectors are needed (ram and the processors are the exception, they draw all their power from the motherboards). For example: For the motherboard you’ll need the 24 (20+4)pin connector, the video card will require an 6 or 8 pin connector (high end cards sometimes require 2), the hard drive and optical drive each will require a SATA (the new standard) or Molex connector. Almost all new power supplies you buy will have the required connectors for the latest cards/hard drives/motherboards etc. They wouldn’t be in the power supply industry long if they didn’t.

SAMPLE BUILD:

Case: $68.99
Fans: $9.99
Motherboard: $138.99
Processor: $199.99
Video Card: $299.99
Memory: $39.99
Power Supply: $69.99
Total: $827.93

The power supply I chose was a OCZ ZT Series 650W Fully-Modular PSU. The system I intend to build will only have one hard-drive and one DVD drive. The video card requires 550w and I’ll add an extra 100w for anything else that may require power and to have some breathing room. The description for the product is very long. As you can see it has two 8(6+2)pin PCI-E connectors for my video, one 24pin connector for my motherboard, one 8(4+4)pin for the processor (this connects to the motherboard as well), 9 SATA power connectors two will be used for my Hard-Drive and DVD Drive and 4 molex cables for fans.

Model

Brand: OCZ

Model: OCZ-ZT650W

Series: ZT Series

Spec

Type: ATX12V v2.2

Maximum Power: 650W

Fans: 1 x 140mm Fan

PFC: Active

Main Connector: 20+4Pin

+12V Rails: Single

PCI-Express Connector: 2 x 6+2-Pin

SATA Power Connector: 9

Modular: Yes

Efficiency: > 85%

Energy-Efficient: 80 PLUS BRONZE Certified

Over Voltage Protection: Yes

Input Voltage: 100 – 240 V

Input Frequency Range: 50/60 Hz

Input Current: 10A @ 115V, 5A @ 230V

Output: +3.3V@30A, +5V@24A, +12V@54A, -12V@0.5A, +5VSB@3A

MTBF: >100,000 Hours

Approvals: UL, CUL, CE, CB, FCC Class B, TÜV, CCC, C-tick.

Dimensions: 5.9″ x 3.4″ x 6.9″

Weight: 4.94 lbs

Features

Connectors: 1 x 20+4-pin ATX
1 x 4+4-pin ESP/12V CPU
2 x 6+2-pin PCI-E
6 x 4-pin Peripheral
9 x 5-pin SATA
1 x FDD

Features

Continuous output rated at a demanding 45°C ambient temperatureBuilt with premium low ESR 105°C electrolytic capacitorsSingle +12V rail for efficient power distribution in your system.Compliant with ATX12V v2.2 standard for worry-free compatibilityA large temperature and load controlled 140mm double ball-bearing fan for whisper quiet operation80-Plus Bronze certified for up to 85% efficiency under real world operating environmentsErP compliant for low power usage in standbyActive Power Factor Correction (PFC) to effectively regulate input voltage

Heavy-duty protection circuitry, (over-voltage, over-current, under-voltage, and short circuit) for protecting your valuable components

Output

+3.3V Max. Current: 30A

+5V Max. Current: 24A

-12V Max. Current: 0.5A

+5VSB Max. Current: 3A

Connector

Main Connector: 20+4 Pin

12V Power Connector: 1 x 4+4 Pin ATX/EPS 12V

PCI-Express Connector: 2 x 6+2 Pin

SATA Power Connector: 9

Floppy Connector: 1

Protection

Over Voltage Protection: Yes

Short Circuit Protection: Yes

Over Current Protection: Yes

Feature

Features

Continuous output rated at a demanding 45°C ambient temperatureBuilt with premium low ESR 105°C electrolytic capacitorsSingle +12V rail for efficient power distribution in your system.Compliant with ATX12V v2.2 standard for worry-free compatibilityA large temperature and load controlled 140mm double ball-bearing fan for whisper quiet operation80-Plus Bronze certified for up to 85% efficiency under real world operating environmentsErP compliant for low power usage in standbyActive Power Factor Correction (PFC) to effectively regulate input voltage

Heavy-duty protection circuitry, (over-voltage, over-current, under-voltage, and short circuit) for protecting your valuable components

Safety Approvals: UL, CUL, CE, CB, FCC Class B, TUV, CCC, C-tick.

Dimensions & Weight