The combined load capacity of the +12V rail is not declared but it equals the sum of the two “virtual” output lines it is split into. So, this PSU can yield 36A (432W) across its +12V power rail.
The Antec website claims that two +12V lines (one of which is connected only to the 4-pin ATX12V connector) ensure stable power for the CPU that does not depend on the consumption of the other components. As I have repeatedly noted in my reviews, this is untrue. There is but one 12V power rail inside the PSU. It is split into two lines at the output in order to make the PSU safer for the user. Thus, there is no talking about the two lines being independent. Except for the tiny difference due to the voltage drop on the wires and connectors, the voltages of the 12V1 and 12V2 lines are almost identical. If one sags, the other sags, too.
The PSU is equipped with the following cables and connectors:
- Mainboard cable with a 20+4-pin connector (50cm long)
- CPU cable with a 4-pin connector (50cm)
- Graphics card cable with a 6-pin connector (51cm)
- One cable with two Molex connectors and one floppy-drive plug (50+15+15cm)
- One cable with three Molex connectors (50+15+15cm)
- One cable with two SATA power connectors (51+15cm)
The wires are tied up with nylon straps into braids. Wires from different braids are entangled near the PSU case.
Together with an APC SmartUPS SC 620 this PSU worked at loads up to 340W (from the mains) and 320W (from the battery). The pair was not stable when working on the battery: the UPS would shut down after 10-20 seconds under a slightest overload. I didn’t observe such problems with this series of FSP products before.
The PSU worked normally at its full load of 500W.
The output voltage ripple is low, far below the allowable limits on the +3.3V and +12V rails. There is almost no ripple at all on the +5V rail.
The cross-load characteristics are normal for this series of FSP power supplies and somewhat inferior to the opposing products: the +5V and +3.3V rails sag quickly as the load grows up and the PSU does not make it to the full declared load for these rails, which is 152W.
On the other hand, this is an insignificant drawback for modern PCs. As you can see, my “reference” configuration hits the “green zone” again. In other words, the voltages deflect less than 3% in the four test modes, from idle to 3DMark06.
Alas, the PSU is not silent. Its fan starts up at over 2000rpm and accelerates proportionally to the load. It is always audible and becomes the noisiest in the system at a load of 200W because the present generation of graphics cards (both Radeon HD 3870 and GeForce 8800 GTS/512) is rather quiet while good CPU coolers are quite a common thing these days. So, Seasonic seems to be wise in using somewhat larger heatsinks in its PSUs.
The PSU set no records in terms of efficiency, yet its efficiency factor is always above 80%.
Unfortunately, the Basiq BP500U is indeed a basic product among the PSUs selling under the Antec brand. Having good electrical parameters, it shows drawbacks the other models in this review are free from, namely high noise and certain instability when working with my UPS. Users may be interested in the junior, 350W, version of the Basiq if it is cheap enough. The senior, 500W, version may only be necessary for top-end configurations. But if you have an advanced configuration, you may want to add some more money and buy a more expensive and better PSU instead.
