With its 750 W ceiling, the Sutai Double Power P4-750W is basically a big brother to the P4-500W. While it has one more SATA connector (two total), it has one less Molex connector. Aside from that, the two power supplies are almost like peas in a pod.
The Sutai Double Power P4-750W did not even last as long as the 500 W model. Alarmed by the weaknesses of the 500 W unit, we began our tests at very low loads. Again, the results suggest a PSU originally designed for a maximum load of 300 W. Looking at the test results at low loads, this becomes rather evident.
It reaches an efficiency of 82% at loads as low as 85 W, a value that more expensive and powerful models would be happy with at this low level. But expecting the $25 Sutai Double Power P4-750W to continue delivering efficiency values like that might be a tad optimistic, even at 300 and 400 W, which is output that should be easy for a 750 W PSU. We were not extremely surprised when the PSU suddenly died of a heat stroke at a load of just 350 W, making further testing impossible.
Compared to the 500 W model, the Sutai Double Power P4-750W is an even bigger shame. While its little brother shut down at low loads, at least it'd fire back up after resting a bit. The 750 W unit overheated after just a short period of testing, and was completely dead after that.