Pros, Cons And Final Verdict
The SF-550F14MG is a high-performance PSU with very tight load regulation on all of its major rails, excellent ripple suppression and quiet operation under normal operating conditions. As far as efficiency goes, Super Flower would need to improve if it wanted a first-place finish. But even with its current tuning it offers adequate efficiency. In addition, the modular cabling design proves to be very helpful during the installation and cable management process. And the LED-lit modular connectors look nice, though you need a windowed chassis to properly appreciate them.
The major downside of this unit is its low hold-up time, which not only fails to meet the ATX specification's requirements, but is also lower than the power-good signal's hold-up time—normally it should be the other way around. We could tolerate a low hold-up time if the power-good signal dropped before the rails went out of spec, but in no case can we tolerate a PSU that reports a power-good signal while its rails are out of spec. We don't know why Super Flower chose to do this, but it surely is a big flaw in this unit and we expect the company to fix it in the next revision of this platform.
It's a shame that such an otherwise-solid PSU is so flawed. This is the main reason we won't be giving an award to the SF-550F14MG.
The SF-550F14MG isn't available in the U.S. anyway. Here, you can get EVGA's 550 G2 instead, which offers similar performance. Notable differences between the two include a slightly smaller fan and illuminated/cube-shaped modular connectors on the SF-550F14MG. EVGA uses only Japanese capacitors, while Super Flower employs some CapXon caps on its modular PCB.
This is the first time we've seen a high-end Leadex PSU without all-Japanese caps, and to be frank, we didn't expect it. More than likely, Super Flower didn't have enough Japanese caps on hand (since they're difficult to obtain), so the use of CapXon caps was forced. Nonetheless, the company should have used Teapo caps instead, which are considered a safer and higher-quality choice. At least the CapXon caps are used in a low-stress area, and the hard part of ripple filtering is handled by Chemi-Con (Japanese) capacitors. We know that many users will be let down once they learn that this Leadex unit doesn't exclusively use Japanese caps.
To conclude, if you want only high-quality caps in your PSU and you also want to avoid the SF-550F14MG's problem with its power-good signal, then stick with EVGA's 550 G2, which uses only Japanese caps and, although it has a lower than 16ms hold-up time, its power-good signal is inline with the actual hold-up time.