X-bit labs

Roundup: 14 Power Supply Units from Thermaltake (page 16)

Category: Other

by Oleg Artamonov

[ 07/28/2006 | 08:34 AM ]

The cross-load diagram for the W0068 looks good except that the +5V voltage might be more stable. Well, that’s nothing but fault-finding because there are going to be no problems with the voltages in practice.

Both low- and high-frequency pulsation can be observed on the PSU’s output. At a load of 450 watts the voltage ripple is 25 millivolts on the +5V rail, 105 millivolts on the +12V rail (over half of this pulsation is at the double mains frequency, i.e. 100Hz), and 35 millivolts on the +3.3V rail.

The PSU uses a Young Lin Tech fan, the DFS122512M model. Its speed is controlled in an linear-like manner, but the PSU is not quiet. The fan speed is about 1100rpm at min load and then grows up to 1800rpm at high loads. The W0068 will suit you if you are not very fastidious about noise, but people who seek complete silence may not like it.

The efficiency of this power supply is very close to the 80% mark, but doesn’t go beyond it. The power factor is quite typical (for a PFC-less unit) at 0.68. I want to note that this parameter is only important for power companies and large organizations with a lot of computers. A low power factor leads to extra loss in the power system, i.e. in the wires, and may even lead to problems associated with distortion of the shape of the line voltage in some cases. This is not a problem for home users. PFC will only make a difference if the line voltage is unstable in your area, but you need an active PFC device with a full range of input voltages, from 90V to 265V, then.

So, the W0068 doesn’t differ in anything important from the above-described W0063. The same design, the same load capacity, and rather close parameters… This PSU is a mainstream model. Its parameters are not exceptional, but it is neatly designed and provides good enough parameters as to satisfy a majority of users. But like with the W0063, if you need as quiet a PSU as possible, you should consider other models. Despite the efficient fan speed management, the W0068 is not quiet.

The choice between the W0063 and the W0068 depends on whether you need active PFC. On one hand, most users don’t actually need it, but on the other hand, the price difference between these two models is only about $3. Of course, the W0068 has slightly better cross-load characteristics than the W0063, but the difference is small and may vary in this range from one sample of the same PSU to another.