New ~550W psu, what is recommended?

[saitrix]

So I have had a good look round on the forums and reviews, it seems like the following psu's are highly regarded. I have decided that my Nexus value 430W is getting a little old and I have lost a pc before from a PSU blowing up!

Corsair RM550x (£70)
Corsair RM650x (£75)
EVGA G2 550 (£80)
EVGA G2 650 (£87)
EVGA P2 650 (£115)

The pc I am using it on is the following spec:

i5-4670k (undervolted 0.1V & cooled by Macho 120, soon with a 120mm Noctua NF-F12)
2x4GB DDR3
Asus Z87-A
XFX 7870 (overclocked but no voltage change)
Fractal Design Define R5 (running 3x140mm case fans)
1x 7200rpm HDD & 1x 840evo SSD

So normally I would say at most I need the 550W. As I am leaning towards the RM550x (due to the price) I noticed how little more it is for the RM650x. Do I gain anything from going to the 650W, for example will the passive mode go to higher wattage? I was thinking it would not as both PSU's create the same amount of waste heat at each wattage level so you would think they both require the same amount of cooling. Is the RM550x the better buy in my case?

Finally I have no want for running SLI/CF and my only possible upgrades is to swap to a lower TDP gpu like the RX480/GTX1060.

[quest_for_silence]

Either the P2 or any RMx (the 650 likely won't bring you anything), or even a Be Quiet P11 (for a price premium).

[lodestar]

Do I gain anything from going to the 650W, for example will the passive mode go to higher wattage?

The wattage at which Corsair say the fan will turn on does vary but only slightly, 225w for the 550x and 260w for the 650x. One point of difference between the two is that more cables are supplied with the 650x, 9 in all rather than the 7 you get with the 550x. One of the extra cables is a for a second graphics card which might be useful if you were planning to go SLI at some point in the future, or at least wanted the option to do so. However since you have no plans to go this route you would only be paying extra for cables that would never be used.

[saitrix]

That's brilliant, I think I will go for the RM650x due to the such small price different and the higher passive mode.

[pino800]

so, how did it turn out in the end?

is it a good unit, any issue so far?

I am in a very similaru situation

[Tilltech]

I've looked into this before, this one is the best quiet PSU for high-end, single GPU PCs.