X-bit labs

ATX Power Supply Units Roundup. Part IV (page 16)

Category: Other

by Oleg Artamonov

[ 04/10/2006 | 09:02 AM ]

The PSU offers the following cables and connectors:

• Mainboard cable with a 24-pin non-splittable connector; 52cm
• Cable with a 4-pin ATX12V connector; 56cm
• Cable with an 8-pin EPS12V connector; 55cm
• Two cables with 6-pin graphics card connectors; 60cm each
• Two cables with two SATA power connectors; 70cm+20cm
• One cable with a Molex connector and one floppy mini-plug; 55cm+20cm
• Three cables with two Molex connectors on each; 55cm+20cm

So, we see the same picture as in case of the HP2-6500PE PSU: there are all the necessary cables present, but if you have an old mainboard with a 20-pin power connector, you’ll have to use an adapter (although i really doubt that the owners of older mainboards will ever go for a powerful PSU like that anyway).

There is no plastic ring around the wires where they go out of the PSU case. Some users have reported they have seen wires losing their insulation due to such design, but I do not think this is a really big problem. It’s really hard to cut the thick and durable insulation with a smooth rolled-in metal edge of the PSU case.

The cables are all hidden in plaited tubes.

The cross-load diagram for this power supply is a treat to my eye. Featuring independent voltage regulation, the PSU never allows any output voltage go out of the acceptable range. Moreover, the output voltages do not deflect by more than 2% from the nominal value, the allowable deflection being 5%! That’s an excellent performance, among the best results I’ve ever seen in my tests.

At full load (600W) the output voltage ripple was 22, 50 and 15 millivolts on the +5V, +12V and +3.3V rail, respectively. The pulsation spectrum differs: only high-frequency pulsation on the +5V and +3.3V, and mostly low-frequency, 100Hz pulsation on the +12V (the lower oscillogram).

When working with an APC SmartUPS SC 620, the UPS would indicate overload at a load of about 365W (AC power source) and 250W (when switching to the batteries). The result is 70W worse than that of the previous model. So when there was a load of 250W on the PSU, the UPS’s overload protection woke up when switching to the batteries and the UPS shut down the computer.

The PSU is rather quiet at power loads of 250W and less (but I can’t call it silent because the hiss of the air is distinctly heard; most PSUs with 120mm fans are much quieter). When the load goes up, the PSU is not just noisy, but actually loud.

To make it clear, I’ve got two regular system cases on my desk and four powerful fans (two 92mm Thermaltake and two 80mm Delta Electronics) to cool the testbed. This arrangement isn’t very quiet even in the big room where there are a few more people and half a dozen more computers besides myself and mine. And the PSM-6600PE managed to make itself heard and prominent above everything else with its irritating loud high-frequency hiss of its fan! By the way, a Sanyo Denki SanCooler 80 fan (part number 9A0812S402) is installed in it.

The PSU is as efficient as the HP2-6500PE (about 84% at the maximum), and its power factor is higher at 0.99.

So, the top-end model in the Gaming Power series leaves an ambiguous impression. It really has excellent electrical parameters like super-stable output voltages, good efficiency, low voltage ripple at high output power, but it is so loud at high loads that I doubt you’d want to use it not only at home but even in office. The problem is not about the noise as such, but about its spectrum, which is shifted upwards and is thus distinguishable against the common chorus of PC fans. It is really annoying for the human ear. You can also encounter problems using this power supply with an UPS. I’d recommend a high-power and high-quality UPS for this power supply for the switching-over to the batteries was done correctly.

On the other hand, the noise factor becomes less important if we talk about a powerful gaming machine with two graphics cards. Few people who own such computers do anything to improve their cooling while the stock coolers of modern top-end graphics cards are generally rather noisy. In this case, the excellent electrical parameters of the PSM-6600PE may outweigh its noisiness.