Seasonic Platinum-1200
We could not help but notice that the top model from Seasonic is almost identical to the Cooler Master V1200, which is not surprising since Seasonic manufactures both of them. Their technical specs are all but identical, and the internal layout proves that these two PSUs are twins. But there are minor differences: The number of connectors, cable lengths, and the fan switch’s labels, where we prefer Seasonic’s scheme (‘Hybrid’ and ‘Normal’) over Cooler Master’s. The Seasonic PSU has two SATA connectors more, but two PCIe connectors less and four Molex connectors less. Except from the motherboard cable, all cables are flat ones, and their lengths are similar to Cooler Master’s cables. Like the Cooler Master PSU there is a single 12 V rail which can supply up to 100 A.
| AC Input | 100-240V, 50-60 Hz | |||||||
|---|---|---|---|---|---|---|---|---|
| DC Output | +3.3V | +5V | +12V (#1) | +12V (#2) | +12V (#3) | +12V (#4) | -12V | +5Vsb |
| 25 A | 25 A | 100 A | n/a | n/a | n/a | 0.5 A | 3 A | |
| Individual Output | Row 2 - Cell 1 | Row 2 - Cell 2 | Row 2 - Cell 3 | Row 2 - Cell 4 | Row 2 - Cell 5 | 6 W | 15 W | |
| Rail Utilization | Sys | Sys | CPU & VGA | |||||
| Combined Output | 125 W | 1200 W | ||||||
| Total Continuous Output | 1200 W | |||||||
| Peak Output | n/a |
Efficiency According to the 80 PLUS Spec
Efficiency for Typical Use Cases
As expected, the similarities of the Seasonic and Cooler Master PSUs extend to the lab test. The minor differences which did show up can be attributed to parts and measurement tolerances. The Platinum-1200 rightfully bears its 80 Plus Platinum logo, and compared to the Cooler Master V1200, it is all but identical electrically. However, its hold-up time is much longer, thanks to larger capacitors. Ripple and noise are similar – perhaps the voltage curve on the Seasonic is slightly better.
Due to their identical genes, it is not surprising that the hybrid fan control behaves identical on both PSUs: At 40 and 200 W, the fan is off. But when it finally started up at 600 W, we were nonplussed by its noise – 42.7 dB(A) is inappropriate for a high-end PSU.
A Closer Look at the PCB
Since the Seasonic and the Cooler Master PSU are all but identical, there’s not much new to say. The primary capacitors do differ – while the Cooler Master V1200 contains one marked 390uF 420V and a few others marked 330uF 420V, all primary side capacitors in the Seasonic Platinum-1200 are marked 390uF 420V. We saw the effect of this change when we measured the hold-up times of both PSUs
