Shortly after purchasing a Pentium 4 based PC back in 2001, my parents had to get it repaired several times because parts kept failing. First, the CPU went out, then the motherboard, and finally the power supply. When the power supply was replaced it only lasted two weeks before the CPU failed and the cycle started again. After a while, Dell decided to replace all three of the parts in one go and the PC kept chugging along until 2011 when we gave it to a family so their kids could do homework. It might still be running. Turns out that a bad power supply had damaged the voltage regulators on the motherboard, which knocked out the CPU and eventually the rest of the motherboard, which then damaged the PSU and ad infinitum.
We say it all the time here. You can't skimp on a power supply, especially in a high end rig, but it's a simple fact that we have to repeat for those who may be reading a power supply review for the very first time. Motherboards are designed to help regulate voltages, but even those circuits will burn out if the power fed to them is unstable. Believe it or not, but as someone who works with microcontrollers and building circuits, I can affirm that too little voltage can be just as deadly to a computer as too much, especially in something so complex and sensitive as a CPU or a motherboard.
Cooler Master's GX II 550 Watt power supply is an 80 Plus Bronze rated PSU. The GX II 550 has been designed to support the power saving features of Intel's Haswell CPUs and will provide USB power to charge mobile devices while the computer's off. Feeding power to the components, there's the standard 24-pin connector to the motherboard, a 4+4-pin 12V supply for the CPU, a pair of 6+2 pin PCI-e connectors, two cables with three SATA power connectors each, and one cable with three 4-pin Molex connectors and a floppy drive power connector. There's a 120mm fan and lots of ventilation to keep the GX II cool. Last, but not least, is the 5V power connector that goes between the motherboard and the front panel USB 2.0 ports on your case. It's priced at $69.99 and comes with a five year warranty.