On the fanless/semi-passive question: I want to avoid fanless because it looks like having a passive PSU would affect the airflow in this case (correct me if I'm wrong!) I would consider semi-passive
I'm not sure about what you meant, if you're thinking to heat evacuation, passive and semi-passive are almost the same, in this respect: when the fan is not spinning, the PSU cannot play an active exhaust role.
On the other hand, I don't think it's fully correct to force/let the PSU act as sort of an exhaust fan, at least because you're heating up the PSU that way: set aside reliability concerns, to not speed up its fan you have to rely upon heat-resilient PSUs, there are a few, and the quality ones usually are longer than 150mm.
If you were thinking to other aspects, feel free to explain them furtherly: take also note that the complete specs of your upcoming build would help to advice, a lot (we need to estimate the actual power draw and heat build up).
Also I haven't looked much into the SFX supplies because I was under the impression that they tend to be louder.
Broadly speaking, it's true: on the other hand, if you're going to comply to the specified clearance, lots of the available ATX PSUs are likely not the quietest ones, so YMMV. The new SF450 by Corsair might be worthwhile
in this respect, but that's far from certain.
Among ATX shy casing units, come to mind the Cooler Master G450M
and the Corsair CS-450M
/ CS-550M, which offer a rather heat-resilient but relaxed fan profile: the main drawback is their questionable parts selection (mainly low tier caps), which doesn't cope well with heath. Another questionable aspect is relevant availability in North America (you didn't stated your location, IIRC). The CM GM series is also noticeably less efficient than 80 Plus gold-rated competitors.
Another option is the Cooler Master V450S
, which offer a modern topology and high efficiency, with better grade components and a slightly more conservative (aggressive) fan controller than the above mentioned PSUs. Relevant main drawback is they're EOL and (as above) north american market availability: they've been replaced by the new, fully modular, Cooler Master V550, with a similar fan profile
at highish temperature.
On the other hand, with 160mm units like Corsair RM550x or Be Quiet E10 500W CM you should play a lot safer, noise wise.
I looked into the SuperNova GS but haven't heard much about it on the noise side. Is it quiet?
In your upcoming setup, it *might* be enough quiet: available data are not completely unambiguous in this respect.
According to JonnyGURU.com up to 31-32°C the GS lineup should warrant a fanless operation range of more than 150W for the 550W
model (probably more than 200W), and of about 270W for the 650W
unit; PC Perspective seems to support those data, with a very low noise increase up to 50% of the rated power and a consistent fanless operation range
, particularly at lower internal temp (PC Perspective test PSU in the 23-40°C range). On the contrary Aris Mpitziopoulos reviews seemingly beg to differ: though at higher temperature he found the 550W to be enough quiet up to 220W
, while rather quiet up to 260W
was the 650W unit, differently from all the other reviewers at lower temperature he recorded a very short fanless operation range for both the 550W
and the 650W
A last information source is KitGuru, which stated a very low noise (for their standards) up to about 270W for the 650W
model: unfortunately their operating temperature to me is unclear
, anything between 25°C and 35°C I suppose.
All in all, the best I can say about a GS inside a PC-Q10 is that "it might be quiet" (though it's expected to be quieter than a Silverstone Strider Gold 550W in most situations, even at 22°C