techPowerUp posted a review on the Corsair VX450W PSU
A quote from the article:
Corsair VX450W Review
Corsair's new VX450W power supply comes with a maximum load of 450W. While this may not sound much it is absolutely sufficient to power most of today's systems. The PSU has a very high efficiency of over 83% which allows the fan to run slower because there is not so much excess heat to get rid of. In our fan noise testing this extremely silent unit leads by a large margin over all other PSUs tested so far.
Corsair VX450W Review