I've been searching for a 400-600W PSU that will fit next to a bottom mounted 140mm fan in a Fractal R4 case. My requirements are standard: efficient, quiet, and reliable. If the PSU fan is facing down for intaking air, then its connectors cannot be at the bottom, otherwise they will be blocked by the fan.

I'll be using NCIX to build my new PC, so my options are limited to this page: http://www.ncix.com/category/power-supplies-ff-1066.htm

I wanted a Seasonic, but the G series are out due to the connector placement and the X-660 XP2 is out of stock. The Be Quiet! Dark Power Pro 10 550W is nearly out of stock, and I'm not in a rush to buy.

My research narrows it down to and Corsair RM650 and Fractal Design Newton R3 600W. Both happen to be semi-passive, and based on my usage their fans won't start unless over 50% load (which most likely won't happen for me). On paper the Fractal is Platinum-rated and some reviews seem to indicate it uses Japanese caps, while the Corsair uses Taiwanese caps. Any thoughts?

All of the seasnoic X series, aside from the 1000W or old 860W, are 160mm, allowing to install the bottom 140mm fan on the R4, i own an R4 + X660 + 140mm bottom fan, yo do need to place them with the fan facing the bottom as the other way around wont fit cause of the location of the modular connectors, i leave you a pic so you get a better idea.



I believe that the Corsair RM are also 160mm, at least the RM450/550/650 (the 750/850/1000 are bigger), by the pictures the modular connectors are in the same disposition of the seasonic, so you will need to install it with the fan facing down.

I don't know why do you compare the RM with the R3, as FD Newton here in Italy are usually far more expensive.
They have not dissimilar performances, but there are chances the RM would run quieter most of the times: so personally I'd go for it.

Only problem with those particular X units is they're overkill and expensive. I have actually been comparing many PSU images together with your image since it's so useful as a reference . It's actually thanks to you for inspiring me on this 3-intake 1-outake fan setup .

Yes, the Corsair RM650's 160mm depth should fit. I wasn't sure whether it's recommended over the others. Also, do you know if the Fractal R4's bottom drive cage can remain in place with a 140mm bottom fan? I wasn't sure since you have yours removed.


The Newton (165mm depth, but should still fit) is also more expensive in Canada (about $30 if I price match other competitors). I just didn't know whether the better quality components and Platinum rating in the Newton is worth buying over the Corsair. Why are chances higher with the RM if both units are semi-passive? i.e. if my peak load won't reach 300W then wouldn't both fans be off?

Set aside I won't bet those fans will be off at 50% of rated power, in a real life scenario, PSU fan controllers are not only load based, but mainly temperature based: from what I read, the FD has a more aggressive one, so when the temperature will rise inside the case, the fan will more likely start to spin.

About quality, the FD has clearly a better stability than the RM, but when we're dealing with either 0.5% or 1.0% regulation on the 12V rail, how much does that actually matter? Only you know your answer: but for the price you will likely pay, personally I would pick a different PSU.

Thanks for your answer