i can't seem to find the Nexus RX 5300 in the UK, though i can find the 6300 - anything known issues with this one? [...] so based on that, would you suggest going for the Nexus 6300 or the Seasonic 660?
The Nexus RX-6300 should be no different overall, just a teeny tiny bit louder according to the graphs on Nexus' site. It will just have a lot of headroom, manifested as components, that you will most likely not need
. Theoretically there's more to go wrong and a higher price you pay for something unnecessary
, but thanks to the 80 Plus certification it should be no worse for efficiency.Based on your preference, I would get the Nexus
, as I have not come across reports of or experienced squealing etc. - especially after the nasty RMA experience with Corsair. I also implicitly trust active cooling over semipassive in prolonged use scenarios.
Regarding the Corsair: the review that says it is a Seasonic unit is from 2008. The caveat in the Recommended list clearly states:
When it comes to the noise they make, PSUs of the same brand, even of the same series, are not that closely related sometimes. While some PSU brands are pretty consistently quiet (Seasonic is a good example), individual models still vary. Some brands are less consistent. This is especially true of brands whose power supplies are made for them by OEMs, often more than one at the same time, for the same or similar series.
My emphasis. In this instance I would not be surprised to learn that between 2008 and now, Corsair has switched to one of the other subcontractors in their employ, possibly a cheaper, less reputable one.
Regarding how they cut costs, I would claim that it's not the parts that cost the most, but the labour
. Skilled, hi-tech assembly labour costs more than cheap, non-skilled, lengthy and tight quality control with large sample sizes costs more than lax, owning your supply chain may cost more than outsourcing etc. The electronic, mass produced parts most likely have cost differences in the tenths of cents and pennies, and as a result will hardly sway prices one way or the other, except in the case of the truly dreadful units where every cent counts. Still, it's probable that lower-rated parts and lower-quality bins would be used by cheaper makers in addition to cutting labour costs.
Warranties are the manufacturers' statements of confidence
regarding the product, but when does it stem from the confidence that your product will last the stated span of time
, and when does it come from the knowledge that your profit margin allows for a number of busted units and post-purchase customer dissatisfaction
? It is probably a bit of both, but I would say the consistent, high-quality manufacturers count on the former first and more than on the latter.
I can't say how much of "Seasonic" goes into a particular design. You'd have to find an expert review for that, like this SPCR review of the VX450: http://www.silentpcreview.com/article751-page3.html
for example. I'm just some amateur DIY and silence enthusiast voicing my opinions and the supporting evidence thereof.
I have had excellent experiences with Corsair support (they even sent me a SATA cable for my HX520 for free!), but my experience with their products' consistency and quality has not been the best. Only RAM I have had fail or be incompatible has been Corsair (3 kits, sockets 775 and 939) and OCZ (1 kit, socket 939).