Power Supply Upgrade

When adding power-hungry cards such as a GPU, check the power supply capacity. While researching a GPU upgrade, the desired GPU performance would require more power than the existing power supply. This PC is a ATX size.

The specifications of the existing power supply should be on a label. Open the PC case and read the label.
Determine what size power supply will be needed (add up motherboard, disk drives, existing peripherals, and new card) to find the required wattage. Research power supplies to find a power supply unit (PSU) size which will fit inside the PC case.
Measure, measure, measure. The existing power supply was about 5 1/2" long.
As the new power supply likely has a fan, carefully determine the fan position and if it will work with your PC case.

Old power supply length


Old power supply width



A Cougar DX500 was chosen as the new power supply. This new power supply has the same width and is about 1 1/2" longer. The power supply fan exits out the back of the unit, near the power cord.

Cougar DX500 power supply


Next, locate the motherboard connector. The existing motherboard connector was 24 pins. The new power supply is a 20 + 4 pin connector. This means the main connector is 20 pins with an additional 4 pin connector.

Mother board connector in top right corner (near the arrow)



If adding a GPU, the card will typically take additional power from a 4 pin power supply connector. Carefully determine what power is needed by the new card, and what is provided by the new power supply unit.

Old 24 pin connector beside new 20 + 4 pin connector



Remove old power supply and carefully install new power supply. Routing power cables may be tricky, so take your time.

New power supply installed, with old power supply in picture


Power on the new power supply and test the PC.