Hello everyone,

I'm skeptical as to whether a 120mm fan really makes up for the added turbulence/smaller heatsinks, but given the prevalence of 120+mm units, I'm reconsidering. I'm interested specifically in the differences between Seasonic units, such as my (80mm fanned) 400ES Bronze vs an S12II or similar.

Details:
I have the 400ES Bronze "retail" version (http://seasonic.com/pdf/datasheet/NEW/Retail/SS-350-400ES%20Active%20PFC.pdf.pdf) powering an ASUS AM3 board in an Antec Atlas case. It has been fairly quiet so far, save for some crackly/rough bearing noise and slight occasional coil whine.

How would a 120mm fanned Seasonic unit compare in terms of bearing noise and turbulence? What about swapping the ball-bearing fan for an 80mm FDB fan (Scythe/Panaflo) of comparable CFM vs swapping to a 120mm (ball-bearing) unit? Finally, do other quality PSU brands (maybe Supermicro) have lower rates of coil whine?

Thanks much!

PS if anyone is interested, I can do a short write-up on the Antec Atlas, though I don't have a Solo to directly compare it with.

Generally speaking, modern 120mm units are really good (at least those "SPCR-grade").
Generally speaking, at a given speed the smaller fans are quieter: so IMVHO it depends most of your workload.

Currently I don't have SS-based 80mm units, but I have two Delta ones, the Antec Signature and the Antec EarthWatts 380.
Compared to my Seasonic S12D (120mm Sanyo Denki ball bearing fan) they are respectively slightly louder and unbearable louder.
I've tested the Signature against an S12-II some years ago, and the former was clearly superior with reference to noise.

I've modded the 380W with an ULNA Noctua R8 running under 1000rpm and it's inaudible, slightly but noticeably better than the S12D.
It works flawlessly since two years, but I use it on a Wolfdale based desktop, with IGP and just a notebook drive (I don't know what could happen to it with far higher load, with reference to reliability).

With reference to the S12-II, I think today it should be a somewhat different model since the S12-II tested by SPCR (and which I know), so YMMV.
Anyway, you might also opt for different units, such as Enermax or Nexus ones (give a look to the SPCR reviews).

Thanks for the great info Luca!

That gives me a pretty good perspective.