Thermaltake Smart M550W Review

Final Thoughts

Pricing

The Thermaltake Smart M550W (SP-550AH3CCB / SP-550M) currently costs £58.20 or £65.99 from two leading UK retailers. Since this is a European product the same version isn’t available in the USA. There is, however, a Smart series 550W power supply that Thermaltake sell in the USA and it sells for a ridiculously cheap $50, but it is worth considering we did not review that unit, it is internally different and so the results in this review are not comparable.

Conclusion

Thermaltake’s Smart M550W is a competitively priced power supply. However, the competitive pricing does come at a performance cost. The ATX specification for ripple is up to 50mv on the 3.3 and 5 volt rails and up to 120mv on the 12 volt rail. We were seeing maximum ripple of around 43mv on the 3.3 volt rail, 33mv on the 5 volt rail and 81mv on the 12 volt rail. These numbers all fall within ATX specification quite comfortably, though the 3.3 volt rail is kind-of close to the limit. Yet those results aren’t that impressive even if they do fall within ATX spec, I’ve seen many other equivalently priced PSUs perform much better. Kicking things up a notch on CrossLoad and we could see that actually the 3.3 and 5 volt rails hold up remarkably well. It seems to be the 12 volt rail that is slack, as shown by its 97mv under CrossLoad. I am no expert on power supplies but it seems likely that group, or shared, voltage rail regulation causes the 12 volt rail to drag the other two down slightly when it is under high load. Of course as we have said at no stage, under real loads or CrossLoad, did the power supply depart from ATX spec in terms of ripple. The performance was always at least 20% under the limit so the power supply still performs okay.

Moving on to voltage regulation and we can see the unit performed very well. The voltage regulation was generally very tight across all rails and there was minimal fluctuation under normal testing. When we pushed the unit under 12 volt CrossLoad things did start to falter with 6.33% droop on the 12 volt rail and 6% “overshoot” on the 5 volt rail. Both of those are outside ATX spec, all the other rails remained within. Of course it is worth noting CrossLoad is totally unrealistic, you’ll never be able to use your system in that way unless you are a total nutter but it is always nice to know that your PSU can handle anything – the Thermaltake Smart M550W cannot. Efficiency was one of the unit’s stronger aspects, it delivered impressive efficiency that is well above the requirements of 80 Plus Bronze and actually closer to 80 Plus Silver. PFC also delivered strong results so we have no complaints there. The acoustic performance of the unit delivered quite a lot which is probably a consequence of the large 140mm fan. Only at 100% load did the unit become noisy and the vast majority of system builders will not have the hardware to ever drive usage that high so generally speaking this PSU will always be silent.

The last point worth considering is this unit’s cable selection. Generally speaking the cables are good quality, at least I really like the modular ones – the hard wired ones not so much but Thermaltake have to cut costs somewhere. Having only two PCIe connectors means you will not be able to do SLI or CFX unless it is a single PCIe connector graphics card, like the R9 270 for example. I would of liked to have seen an extra couple of PCIe 6+2 pin connectors for good measure. Other than that I think the cabling is good for a unit of this price.

Pros

• 3 Year Warranty
• Good voltage regulation
• Hybrid/Semi-Modular
• Affordable
• Good modular cables
• Relatively quiet
• High Efficiency

Cons

• Disappointing ripple suppression relative to competition
• Poor Crossload performance – voltage droop and high ripple
• Could benefit from more PCIe connectors

“Thermaltake’s Smart M550W power supply is a decent offering for a budget power supply unit. Intended for an entry level or mid range system it has all the main features you’d need including 80 Plus Bronze efficiency, a modular design, good quiet cooling, affordability and a 3 year warranty. Relative to the competition the Thermaltake Smart M550W is lacking in ripple suppression and voltage stability at extreme loads but in general this is still a competitive power supply that is worth considering if you’re looking to build a sub-550W system.”

Thank you to Thermaltake for providing this review sample.