Our load tests leverage a couple of FAST ATE active load testers and a variety of other equipment such as a hotbox, oscilloscope, power conditioner, temperature probe and a power consumption meter. You can read more about our standard testing approach here.
Our first five tests represent incrementing classes of modern gaming systems with the last test catered to the full spec of the power supply at up to about 1 kW. We measure voltage output at each load, ripple and efficiency. Now, for the Tagan SuperRock 880 Watt results:
The Tagan SuperRock 880Watt power supply delivered some decent results. As expected, the 12V performance was excellent. Even with 23 and 24 amps on the PCI-E rails in Test 4 and 5, the 12V performance remained above 11.80V. Very nice. The ripple on the rails were so low I had to double check the equipment to make sure something was not loose. After a double take, ripple results proved to be excellent with a 35mV result against the permitted ATX standard of 120 mV. The 5V performance also operated without a hitch. Solid results throughout. Ambient or at 50C, the unit operated perfectly on the 12V and 5V outputs. That was the good news, now for the bad news.
The 3.3V results were disappointing. The Tagan TG880-U33II did well up to 5.5 amps, but once I bumped 3.3V loads to 9 amps, things fell apart. This should not have been an issue as it only represented one third of the 3.3V capacity, especially after getting such good results on the 12V and 5V output. I actually went back and re-ran all the tests and double-checked the 3.3V output with a Fluke multi meter with the same result. Tests 4 and 5 both yielded 3.3V output below ATX standards. And, oddly enough, 3.3V output was worse on the ambient load tests.
I thought it may have been due to a possible overload on the 12V PCI-E rails that dragged down the 3.3V output somehow, but in Test 6 the PCI-E loads were only 18 amps and we saw the very same 3.3V output result. I thought it may have been me, but after plugging back in another power supply that did well on the 3.3V tests, it did so once again. The problem definitely lay with this unit. Ah well, they can't all pass.
So, what about efficiency? - The Tagan TG880-U33II definitely proved that it deserved the 80 Plus Bronze rating (20% load - 82% or higher, 50% load - 85% or higher and 100% load - 82% or higher). Normal use (Test 3) saw efficiency around 88%. Wow. In fact, tests bear out that the unit would have actually qualified for the 80 Plus Silver certification. Now, if it was not for the low 3.3V output, this unit would have scored very well for this class of power supply.