Of course, the manufacturers make use of this virtual division of the +12V power rail for marketing purposes, too. They promise that two (or more) +12V output lines ensure unprecedented wattage, stability, etc. This is wrong, of course. In a majority of PSUs there is but one +12V power rail inside. It is only at the very output pf the PSU that it is split into multiple output lines by means of current limiters.
The VX450W doesn’t have this kind of splitting. It has a single +12V power rail with a maximum current of 33A.
The PSU makes those amperes available to you through the following cables and connectors:
- Mainboard cable with a 20+4-pin connector (58cm long)
- CPU cable with a 4+4-pin connector (58cm)
- Graphics card cable with a 6-pin connector (58cm)
- Two cables with three Molex connectors and one floppy-drive plug on each (45+15+15+15cm)
- Two cables with three SATA power connectors on each (45+15+15cm)
The cables are all sleeved. They are sufficiently enough, and there are two SATA cables for your hard and optical drives. The downside is that the PSU offers but one graphics card connector. The total output power of 450W is quite enough even for a dual-chip graphics card, let alone a GeForce 9800 GTX that has two power connectors, too. But you will have to use an adapter if you’ve got such a card.
The Molex connectors are straight whereas the SATA connectors are T-shaped (like shown in the photo above) in the middle of the cable and straight at the end. There have appeared a number of system cases where hard drives are installed crosswise. The T-shaped connector is small and proves to be handier then because you don’t have to bend the cable at an angle of 90 degrees right at the connector.
The PSU had no problems working continuously at any load from 50 to 450W.
The output voltage ripple at full load is within the norm (which is 120 millivolts for the +12V rail and 50 millivolts for the +5V and +3.3V rails) but the oscillogram shows occasional short spikes of voltage. They are not going to affect the stability of operation, though.
A cross-load diagram (see below) shows the effective values of the three main output voltages depending on the distribution of load among the different power rails of the PSU. As I wrote above, the power rails are not independent from each other in a PSU with joint voltage regulation.
The +3.3V voltage is very stable in the VX450W because it is the only one to have a dedicated regulator. The +12V voltage is good, too. What is especially nice, this voltage sags by only 2-3% when there is a high load on the +12V rail. The +5V voltage sags quickly as the load grows up and violates the permissible limits.
This is not a big problem, though. The combined load on the +5V and +3.3V rails is not higher than 40-60W in a modern PC system, and the output voltages of this PSU are all within the norm in this load range.
The PSU boasts superb efficiency in our 220V power grid. It is 79% efficient at a load of 50W and over 85% efficient at 100W and higher! The maximum is high, but I am even more pleased to see that the efficiency depends but little on the PSU load.
As I wrote above, the PSU is cooled with an Adda AD1212MB-A71GL fan. Its speed is about 865rpm at loads below 250W and then grows up steadily, reaching a maximum of 1860rpm. The PSU isn’t exceptional in terms of noisiness even as Corsair’s PSUs go, yet its result is good. The VX450W is almost silent at low loads.
Thus, the Corsair VX450W is a good and neat medium-wattage power supply that would suit perfectly a system with one graphics card. It offers a full selection of cables and connectors, delivers good electrical parameters, and works quietly at loads below 250W.
At the time of my writing this the VX450W cost about as much money as the popular ZM460B-APS from Zalman. Corsair’s product looks quite competitive to it.