Cables and Connectors
The Seasonic SS-300TGW is equipped with the following cables and connectors:
- One mainboard cable with a 20+4-pin connector (30 cm)
- One CPU cable with a 4-pin connector (40 cm)
- One cable with a PATA power connector and a floppy-drive plug (35+15 cm)
- One cable with a SATA power connector (30 cm)
- One cable with two SATA power connectors (34+20 cm)
Oddly enough, this larger PSU has fewer cables and connectors than its Mini 1U counterpart that has the same wattage rating. To be exact, the SS-300TGW lacks one PATA and one SATA power connector which are present in the SS-300M1U.
Considering that there are compact computer cases that can accommodate more than three drives (including an optical drive), we can’t appreciate this reduction in the number of available power connectors.
The Seasonic SS-300TGW has the same specs as the SS-300M1U, which is no surprise since both have the same platform and wattage.
It complies with the 80 PLUS Gold standard, too.
Working together with the APC SmartUPS SC 620, this PSU was stable at loads up to 300 watts when powered by the mains but could switch to the UPS’s batteries at loads no higher than 285 watts.
Cross-Load Voltage Stability
The Seasonic SS-300TGW is less successful in this test than the previous models that share the same platform, yet each of its voltages remains within 3% of the required level anyway.
Output Voltage Ripple
The output voltage ripple is almost the same as with the SS-300M1U. It is only more or less strong on the +12V rail and always remains far within the permissible limits.
Temperature and Noise
The Seasonic SS-300TGW is cooled by an 80x80x15mm ADDA AD0812MB-D90 fan which has a rated speed of 3500 RPM.
As opposed to the previous PSUs, this model didn’t prevent us from measuring the speed of its fan.
The fan was actually idle until a load of 120 watts. After that, it would turn on for brief periods of time which eventually got longer and longer as the PSU load grew. The fan worked constantly at 50% and higher loads. While working constantly, the fan steadily accelerated from 650 RPM to 1600 RPM. A 120x120x25mm fan would be uncomfortably loud at such a high speed, but the low-profile 80mm fan was barely audible.
The Seasonic SS-300TGW is very quiet throughout the entire load range, being preferable to the same-wattage SS-300M1U whose fan is downright loud at full load.
Efficiency and Power Factor
The Seasonic SS-300TGW is 88.1%, 91.9% and 91.6% efficient at the reference loads of 20%, 50% and 100%. Thus, it meets the 80 PLUS Gold requirements. The peak efficiency of 92.3% was observed at a load of 101 watts.
The power factor was 99.4% at full load.
The standby source copes with its job without a single problem.