s12iii 500w vs cxm 550w

hello_there_123 · July 5, 2019

Which one is technically better in performance/quality? S12III has dual mag-amp and (likely) missing OTP but the cxm is double forward.

OrionFOTL · July 5, 2019

There's a review here: http://www.f14lab.com/2019/05/review-seasonic-s12iii-500550650.html?m=1

The load regulation is excellent (0.5% on 12V), but the ripple is high (60mV and almost 80mV on 12V on 500W and 550W models). Crossload is also excellent, deviating less than 0.5% at full load on 12V.

Unfortunately it doesn't include the most important testing, the transient response.

The bridge rectifier is a little cheap IMO. it's 8A in 500W and 10A in 550W, both at 100C and from a questionable company. I think they should bump the former to GBU1006 and GBU1506 or GBU1508 for the latter, or stay with GBU1006 but rated at 150C.

The PFC FETs, LLC controller and secondary side rectifiers all come from companies I barely heard about. Clearly they wanted to save money instead of using popular Champion CM6901 and having Infineon, PFC or ST for rectifiers. Who are MHCHXM? At least the 550W has MOSPEC.

It also uses passive rectification, while Corsairs use synchronous rectification.

I am concerned about the placement of several filtering capacitors, the cables are covering them up and the air may not reach them as well as others.

I also wanted to check the position of the +5VSB rectifier but can't see it anywhere.

Since we still don't know the transient response or if the protections work, I'd say the testing is still incomplete/inconclusive and it's not an informed purchase yet.