When selecting a chassis to house a game rig, we look for just the right mix of features and styling. It's important to have sufficient room for expansion, quality case design, plenty of fan mounts to keep things cool, and maybe a window or two for showcasing our expensive components and immaculate wiring jobs. But how much attention do we give to the power supply--that "brick" that keeps the juice flowing to all our PC's parts? Most often, not enough.
The power supply unit--PSU for short--is usually the last thing we consider when upgrading our PC. That's a big mistake. To perform its job the power supply needs to provide sufficient electrical energy to the computer's various parts. While guidelines exist for determining exact requirements, they're based on power drawn from each component--information that's not always readily available. Yes, you can do the research and apply the formulas to derive exact specs, but that's really not necessary; general recommendations will suffice.
While the average computer may get by with a PSU rated at 200-250 watts, those running the high-end components found in game rigs require substantially more power. Personally, I recommend employing a PSU of at least 300 watts minimum regardless of the hardware installed in your system. For high-performance computers--those featuring cutting-edge CPUs and video cards--it's not unreasonable to incorporate a unit of 350-400 watts or higher. With power supplies, it's better to err toward overkill than to end up with an underpowered unit.
How can you tell if your current power supply is adequate? Well, unexplained behavior and system crashes can result from a PSU with insufficient wattage, as well as from one of dubious quality. If your PC misbehaves on a regular basis and other components have all passed muster, it's worth your while to consider a power supply upgrade.
In addition to overall wattage, take into account a unit's weight. Heavier power supplies tend to incorporate higher-quality components, including larger capacitors, thicker wires, a bulkier transformer, and bigger heat sinks (which do a better job of whisking away heat). Also, make sure your power supply features the appropriate connectors. It should have both the main 20-wire ATX power connector and a second four-wire, 12-volt power connector.
If you're using Serial ATA hard drives, select one that sports the newer SATA power connectors. Otherwise, you'll need to employ Serial ATA power adaptor cables. A final consideration is the noise factor. With dual fans running constantly, PSUs are one of the noisiest components in your PC. Just as quiet-case options exist for those wishing to put a damper on noise, power supplies are available that offer quieter operation thanks to near-silent-running, heat-sensitive, and single-fan designs. As long as power output is sufficient, I highly recommend these more tranquil alternatives.
When selecting a PSU, choose one that's good for the long haul. Pick a model with enough wattage to handle your present requirements, as well as one capable of dealing with anticipated upgrades. Quality units are available from Antec, Enermax, and PC Power & Cooling, among others. As for cost, depending on whether it's a standard, performance, or specialty PSU, you can expect to pay about $60-80 for 300-350-watt models and $100-150 for those offering 400-550 watts.
