AMD Phenom X4 9850
Biostar TF8200 A2+
2x1Gb OCZ Titanium
EVGA GTX 260
3x74Gb WD Raptors
Swiftech Apogee Drive
DVD+RW and Floppy Drives
6 120mm fans and assorted lights
Wattage was measured using a Kill-a-Watt meter and voltage readings were taken with a Fluke multimeter directly at the connector. Idle measurements were taken after a fresh reboot and with no activity on the system. Load conditions were generated using Folding@Home SMP and GPU clients, Windows Defrag and Roxio Creator running simultaneous operations.
The Tuniq Potency 750W power supply remained nearly unaffected by any conditions placed on it. There was no fluctuation on any of the rails at either load or idle states, the readings stayed at constant values during all observations. Likewise there was almost no voltage change between idle and load conditions. Only the +12V output dipped slightly on the PCIe lines under load, and this by a mere 0.02V max, or roughly 1/10th of 1% drop.
The Tuniq 750W continues the quality of the Potency series with increased performance, uncompromising voltage regulation and the latest standard in efficiency, 80-plus Bronze. The CSCI (Climate Savers Computing Initiative) efficiency rating sets targets that manufacturers meet or exceed Bronze level for 2009, Silver for 2010 and Gold by 2011. The Bronze level raises the bar for standard 80-plus certification, indicating the power supply must meet or exceed 82-85-82% efficiency at 20-50-100% load. Silver calls for efficiency ratings of 85-88-85% and Gold at or above 87-90-87% at the same load levels.
The fact that the Potency 750W carries nVidia SLI Certification and Active PFC (Power Factor Correction) is nice too, although in recent years we've come to expect this level of quality from even mid-range units in the 500-750W bracket, as we saw on the Potency 550W reviewed last month. The Delayed Fan-Off feature is similar to some designs we've seen before, although not one commonly implemented. Also there seems to be some discrepancy in the delay and whether it is time or temperature based. It was noted in testing that the Potency fan stopped immediately upon power off, it did not continue to run for two minutes after as the label indicated, however it is not likely the unit was in excess of 50° C so our assumption is that Tuniq's website and packaging is correct and the fan delay is based on temperature, not time.
When it comes to performance, the Potency 750W never skipped a beat. It easily ranks among the top five power supplies I've ever tested based on stability. Readings were slightly above spec but not abnormally so, within 1½-3½% of rated specification. And we'd definitely prefer to see these run slightly high rather than low, especially given our test loads of 20-50% of the unit's maximum capacity.
I'd like to see Tuniq address the modular connector issue, making use of a 20+4 ATX and 6+2 PCIe that allow the sections to attach together. In particular the ATX due to the limited use for a 20-pin connector on modern motherboards, especially with a power supply with this high of a capacity. But other than that, and my usual complaint about the stiffness of mesh-wrapped cables, there's little else to dislike.
I found the Potency 750W available for under $120, which already puts it at the bottom of the price scale for a quad +12V, 700-800W power supply. And there's a $40 rebate currently offered on the 550W and 650W models, so it's quite possible you might find the 750W included in that offer at some point in the future. Even without a rebate it's definitely a good buy and easily earns the OCIA.net Seal of Approval.