The fresh 600W FSP Dagger has a number of strengths, chief among them being its quiet operation. That's hard to find in an SFX-based power supply. In addition, it uses fully modular cabling, its fan looks to be of high quality, and the price is decent for this category's standards. If it wasn't for the 3.3V rail's ripple filtering problem, this unit might have earned a recommendation.
However, there looks to be something wrong with the 3.3V board. We even tested two units to eliminate the possibility of a bad sample. Hopefully FSP looks into this matter quickly; it's a shame to have a minor rail destroying a good overall performance. Another matter that needs attention is the very short hold-up time. Of course, we understand that the form factor's restricted dimensions don't allow the use of a larger bulk cap without redesigning the whole board from scratch. At least the power-good signal is accurate. This is important because we have seen plenty of PSUs with inaccurate or "fake" signals that try fooling the system by making it believe rails are within the ATX spec when they aren't.
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As mentioned, this unit's major asset is its quiet operation. You could also add the solid performance of its +12V rail, along with the satisfying transient response. Again, the SDA600's price is decent, considering what this product offers and the price tags of its competitors.
The competition is extra-tough though, and Corsair's SF line really raised the bar in this segment. If ripple suppression was under control across every rail, then the SDA600's performance would be on-par with your other options. That's not the case, though. The SFX form factor surely imposes many compromises during the design phase, and it doesn't allow for high-end performance. But at the very least we expect every SFX PSU to keep its load regulation and ripple performance within the ATX spec's limits.
Finally, we noticed that the SDA600's finish is easy to scratch, so you need to be careful with it during installation. It'd also be good to see FSP address the single EPS connector and limited number of PCIe connectors. With 600W capacity, this PSU won't have a problem supporting a couple of strong graphics cards requiring two PCIe connectors each. Thus, we strongly believe that FSP should provide more cables/connectors. Most manufacturers unfortunately don't share our opinion, so they limit the number of cables included with their high-end SFX implementations.
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