Picking The Right Power Supply: What You Should Know

Example 1: The Office PC

Test Case 1: Office PC

Here’s a look at our standard office PC.

Office PC
Intel Core 2 Duo E8400

Abit I-N73H
2 x 2 GB DDR2 Kingston Value RAM
Hard Drive
1 x 500 GB Western Digital Caviar Blue
Optical Drive
DVD burner
External Devices
Mouse, Keyboard
Power Draw, Idle
53 W
Power Draw, Normal Load
90 W
Power Draw, Full Load
122 W
Power Meter
Energy Logger 4000 (Conrad Electronic)

• Long-term measurements
• Monitoring
• Consumption measured up to 1.2 kW

Our goal is to find a suitable power supply for this job. We’ll have to ask our readers for forgiveness here, as this article originated with our German team from Stuttgart. While some of the power supplies used by our colleagues may not be available in the US, they still serve to illustrate the point quite well.

Also, we were hoping to use Huntkey’s Jumper 300 W 80 PLUS Gold as our standard. Sadly, the review sample we were promised got stuck somewhere between China and German customs and didn’t make it to the lab in time for this piece. That’s why the Super Flower 450 W Golden Green is taking its place today, despite being a bit on the beefy side for the job. So without further ado, here are our candidates:

Standard ATX 420 W
$14 (€9.90)
LC-POWERLC6350 Super Silent 350 W
$28 (€19.90)
Be QuietPure PowerL7 300 W80 PLUS
$45 (€32.00)
RasurboReal & Power RAP 350 W 80 PLUS
$49 (€35.00)
Super Flower
Golden Green 450 W
80 PLUS Gold
$83 (€59.00)

Big Charts For Our Smallest System

Now for the big reveal. How do our various contenders stack up? Well, have a look for yourself. There are certainly some pronounced differences:

Nineteen watts separate the best and the worst power supply at idle, with Be Quiet and Rasurbo taking the top spots. The Gold-certified Super Flower model comes in third, with the two cheapest PSUs bringing up the rear.

That ranking doesn’t change much when we look at a normal usage scenario, where the difference between the first and last place shrinks to 11 W. However, Rasurbo and Be Quiet trade places, while the rest of the field stays unchanged.

Under load, the delta between our top performer and the worst offender increases to 14 W, with the Super Flower unit taking the lead ahead of Rasurbo and Be Quiet. Meanwhile, it seems that the efficiency curve of the super-cheap Hardwaremania24 PSU starts to fall off again, exposing this model as a rebadged 250 W model. If you want to try for 300 W with a PSU like that, keep a fire extinguisher handy.


In all three scenarios, the 80 PLUS-certified models take the top three spots. Interestingly, the Gold-certified Super Flower only comes out on top under full load. In this case, it doesn’t seem as though its higher price is really worth it. To be fair, it is penalized to some extent by being the highest-capacity model in this group. Super Flower does have one advantage, though, since its model is semi-passive. Under these loads, the fans don't spin up at all, making the Golden Green 450 W an interesting choice for a silent build.