The Super Flower or the Kingwin 550W.

Seasonic has a huge problem with coil whine, despite whatever SPCR got as review samples, I recently bought a 660W platinum Seasonic and the coil whine is eardrum piercing high-pitch torture, audible at 5 meters (>16 feet for you North Americans). Three RMA's later (checked serial numbers, all different units) and the same problem every time. My brother had a X-650 Gold that also had coil whine (more of a turbulent less high-pitch noise though, less annoying than the Platinum at least). I'm done with Seasonic and all manufacturers that source their parts from Seasonic. It's not worth the headache.

I've heard nothing about coil whine on the Super Flower or the Kingwin on the other hand.

I've heard nothing about coil whine on the Super Flower or the Kingwin on the other hand.

High-pitched whine
Pros: None so far
Cons: I was hoping this wouldn't happen to me, but my PSU is producing the high-pitched whine others have mentioned. Not 100% modular

High Pitch Whine
Pros: It...supplies power.
Cons: I purchased this exorbitantly priced PSU precisely because I wanted to avoid the high pitched coil whine. My unit is VERY audible.
My trust was misplaced.

This power supply works great, except for a very high-pitched whine some people can hear. Now a word of caution before you switch to any fanless power supply. Consider what it will do to the airflow inside your case. You'll be taking away a major source of cooling, replacing it with additional heat which will somehow need to be removed. (Note the big heat sink on the side of this power supply. Where do you suppose that heat is going to go? Yup, into your case.) That's a double-whammy many people don't consider. After I installed this unit, the temperature inside my case went up considerably, necessitating adding another fan. Now my computer is even noisier than before! So what was the point of my buying a fanless power supply???

Since KingWin sells an almost identical unit with a virtually silent fan, I recommend considering getting that instead. It's quite a bit cheaper, and will keep your system significantly cooler. As a computer geek with gobs of experience, I can tell you the biggest threat to your system is heat. Want your system's components to give you years of trouble-free service? KEEP THEM COOL!!!

P.S. If you have one of the newer CPUs and motherboards in your system, this power supply may work just fine. Unfortunately, I built my own HTPC/DVR way back in 2006. Its now ancient Pentium D 805 CPU alone can easily generate 95 watts. Add that to the old front-side bus on the motherboard and memory modules with their own cooling fins, and I have a virtual toaster-oven inside my computer's case! So for me at least, a fanless power supply wasn't such a good idea..