On the top of the PC Power and Cooling Tubo-Cool 510 SLI are two small holes which allow external access to a series of internal voltage regulating potentiometers for making adjustments to the +3.3V and +12V power lines. On the left-hand side is a third small hole which allows access to a potentiometer for making adjustments to the +5V line.

When computer systems are heavily overclocked, the extra power draw can cause drops in any of the 3.3V, 5V, and 12V supply lines that some users may wish to compensate for.

PC Power and Cooling is well known for addressing this aspect of PC power delivery which is specific to heavily overclocked PCs (ie, if the PC is not overclocked, there is no reason to make any voltage adjustments). Users are thus able to fine-tune the voltage tolerances for the best possible delivery of power on each of these three power lines for their specific system loads.

Inside, the Turbo-Cool 510 Express/SLI is a maze of electrical components and heatsinks, which explains the weight of the unit. Note the internal voltage regulating potentiometers mentioned earlier, as well as the beefy heatsinks that PC Power and Cooling has used with its internal circuits.

The AC power socket is also appropriately EMI shielded and filtered - this is one of the simplest tell-tale signs of a good PSU manufacturer. Cheap powersupplies will often lack any attempt at EMI filtering on the AC power socket.

The 80mm exhaust fan used with the PC Power and Cooling Turbo-Cool 510 Express/SLI for venting is fairly quiet, but louder than other power supplies we've reviewed lately which use 120mm internal fans with lower RPM speeds. In this case however, there isn't enough space inside the PSU for a large 120mm fan to be used, the company has put emphasis on the electronics which deliver power rather than sacrificing that for the space necessary to install a larger cooling fan.

Also note that a black wire fan grill has been used, rather than a punched out sheet metal fan guard. Wire fan guards are known to have very little air flow resistance, and do not create any extra noise. The Turbo-Cool 510 Express/SLI is not marketed as a 'silent power supply,' but it's hardly intrusive either. Next to your ear you will notice it, but not under the desk in your case.