FSP Dagger Pro 850W SFX

Today we're putting the FSP DAGGER PRO 850 W power supply on our test bench. We recently have tester their 1200 W ATX unit. Besides the PSUs, they also make some chassis and the UPSes. The series was introduced at the end of August '21, so it's less than a year on the market. This fact shouldn't make it obsolete yet, as a revolution will happen in the coming months due to the implementation of the PCI-Express 5.0 generation's power connector.

FSP revamped its Dagger Pro line, and the flagship model with 850 W maximum power output fares well enough against the competition. It is one of the strongest SFX PSUs available on the market today, and it is impressive to see such high power output from such a compact platform. Good parts are used internally, but soldering quality could be better. The cooling fan and the few electrolytic caps on the primary and secondary sides are of high quality, and the same goes for the MOSFETs and SBRs. I have to admit I am not a huge fan of the ACRF (Active Clamp Reset Forward) topology—it is not a top performer because it focuses on keeping the production cost low while increasing efficiency. Still, this Dagger Pro unit achieved relatively high overall performance that could be even higher if transient response were better. In general, ACRF designs don't do so well with transient loads, which a PSU will have to deal with 99% of its operating time. On the other hand, the ACRF topology achieves long hold-up times using smaller bulk caps than those typically found in PSUs.