Corsair SF1000 ATX v3.1 PSU Review – Small power dwarf for thirsty ITX builds

1 - Introduction and technical data 2 - Unboxing, cables and protection circuits 3 - Teardown: Topology and components 4 - Load Regulation, Ripple Suppression 5 - Transient Response 6 - Hold-Up Time, Timings, Inrush-Current 7 - Average Efficiency and PF 8 - Noise and fan control 9 - Summary and conclusion

Unboxing, product pictures and scope of delivery

My test sample arrived in a plain cardboard box, but since I visited Great Wall’s production line in 2023, I had the opportunity to take a photo of the box, which I can now share. As you can see, there is no 80 PLUS badge, only Cybenetics. Corsair has decided to drop the 80 PLUS certification system because it is outdated and very expensive and go with Cybenetics. They can invest the money they save by taking this step into research and development and make even better products. Just saying…

01 SF1000-Box

The dimensions are very compact since it’s an SFX unit, and it’s good to see a die-cut fan grille with large perforations that increases airflow. The narrower the fan grille is, the harder it is for the fan to get air, so it has to spin at a higher speed and generates more noise. The modular panel on the back houses ten power sockets. Instead of a native 12V 2×6 socket, Corsair uses 2x 8pin micro-fit sockets, which are more tolerant of physical “abuse”.

01 psu_top_front-1

02 psu_front-1

03 psu_side-1

04 psu_bottom-1

05 psu_label-1

06 psu_top_rear-1

07 psu_rear-1

08 psu_standby1-1

09 psu_standby2-1

10 psu_standby3-1

Don’t expect long cables in an SFX unit as they are designed for cases with limited internal space. Here you might wonder why the SFX to ATX adapter is included with the product. It is probably intended for users who want to buy Corsair’s standard Type 5 cables to install this power supply into a regular ATX case. With longer cables, you can expect slightly lower efficiency and increased voltage drop due to the increased resistance, especially at high loads. For this reason, many manufacturers send devices with super-short cables for 80 PLUS efficiency certification. This cannot be the case with Cybenetics as the above cable description table is included in all reports.

01 box_cables-1

02 cable1-1

03cable2-1

04 cable3-1

05 cable4-1

06 cable5-1

07 cable6-1

08 cable7-1

In tabular form it reads like this:

Protection circuits

The trip points of the 12V rail overcurrent protection are conservatively set, and the same applies to the trip points of the overpower protection. The only problem with this is that the trip points are higher at hot temperatures than at cold temperatures, whereas normally it should be the other way around. Also, the OCP trip points on the secondary rails are set very high. There is no reason for such a high current, especially at 3.3 V. To make matters worse, the OCP trip points on the secondary rails are quite close to each other in cold and warm conditions.

On the next page we go inside, please turn the page!