INTRODUCTION

   Small form factor PCs may have been quite popular when i first started doing reviews (primarily as HTPCs) but they were never really for me, mainly due to their limited interior case space. Still, there's no denying that there's an increasing segment of the market that favours them because of their compact size and this is also why we've lately seen the introduction of more hardware components compatible with micro-ATX and mini-ITX cases. SFX power supply units in particular have significantly risen in popularity since 2020 and today with me i have one of the highest acclaimed models currently available in the market, the Focus SPX-750 White by Seasonic.

   Sea Sonic Electronics Co., Ltd was founded more than 40 years ago by engineers. Since its early beginnings the company has rigorously maintained its focus on the research, development and production of technologically advanced, high quality products. In 1981 Sea Sonic expanded into the production of PC power supplies to become one of the first manufacturers in this market. Soon after, the manufacturing of high quality and performance PC power supplies became the core identity of Sea Sonic.

   The Focus SPX line of SFX power supply units is available in black and white colors and includes 650/750W output models (just 750W for the white version) all of which are fully modular and feature the 80 Plus Platinum certification (92% electrical efficiency). Other features include Seasonic’ s three-phased thermal control for optimal balance between silence and cooling (three modes, fanless, Silent and Cooling), APFC (active power function correction), DC to DC design, 100% Japanese aluminum capacitors, gold plated connectors, 92mm fluid dynamic bearing fan and several industrial grade electrical protections including OPP (over-power), OVP (over-voltage), UVP (under-voltage), SCP (short-circuit), OCP (over-current) and OTP (over-temperature). The Focus SPX-750 750W model which i have here with me can deliver up to 862W (peak) and sports a strong 62A single +12V rail which can deliver 99% of the units’ total power output - 744W (minor rails have an output of up to 118.6W). Finally, Seasonic covers their entire Focus SPX line of power supply units with a really generous 10-year limited warranty.

SPECIFICATIONS AND FEATURES

PACKAGING AND CONTENTS

Seasonic uses a small black box that just has their logo at the front right over the model name and the warranty period.

The specifications of the SPX-750 along with numerous certifications and barcodes are all on the left side of the box.

Taking a look at the base of the box we see the product features printed in 11 languages.

Two graphs are located at the rear of the box along with several in-depth explanations about some of the product features.

Opening the box reveals the power supply unit which is placed inside a synthetic bag and between two black foam spacers.

Along with the SPX-750 power supply unit and its power cord inside the box you'll also find the modular power cables (again, placed inside a synthetic bag), SFX to ATX adapter, 8 cable ties, 3 cable straps, 9 mounting screws, coupon sweepstakes card and the user manual.

THE SPX-750 WHITE EXTERIOR

Seasonic has equipped the SPX-750 white with white colored modular cables all of which are braided (and high quality braiding at that).

The SPX-750 White is a standard SFX unit that measures 125mm in length, 100mm in width and 63.5mm in height.

At the top (or bottom, again depends on how you see it) we find the 92mm fluid dynamic bearing fan.

Both the company and model names are printed on both sides of the enclosure.

The units electrical table is placed on a sticker located at the base of the enclosure.

The unit has a total of 9 modular connectors which are both different in size and tagged.

Moving at the rear we find the usual honeycomb perforation along with the on/off power switch and the power port.

THE SPX-750 WHITE INTERIOR

The 92mm FDB (fluid dynamic bearing fan) is made by Hong Hua and can spin up to 3500RPM.

Even though the SPX-750 is a very compact PSU still the layout is quite clean.

The main capacitor is manufactured by Japanese Rubycon and is certified for use up to 105 degrees Celsius.

Secondary capacitors are manufactured by both Japanese Rubycon and Nippon Chemi-Con and are also certified for use up to 105 degrees Celsius.

TEST BED

TESTING METHODOLOGY

     Using a dedicated measurement instrument such as a Chroma or a SunMoon to test power supply units is without doubt the most ideal and accurate way (not to mention the fastest) to do that currently. However, it's certainly not the only way there is and so pretty much anyone can test a power supply unit just by using a test rig. Certainly, limitations do apply and so you can't really push a 1000W power supply to its limits if your system only uses 500W at peak loads and that's why over the years we saved certain hardware components for the purpose of building a dedicated PSU test rig. True it may not be as accurate as the above mentioned solutions but it comes really close and is in fact much closer to real world usage. So as always, we ran several games with maximum graphic options enabled at a resolution of 2560x1600 in order to stress every hardware component and increase the overall power demands of the system. The Passmark BurnIn Test was also used to overstress the components in an effort to provide the most accurate results possible. As a final test we also used the latest OCCT 4.4 software and its dedicated PSU testing suite since it can really bring a power supply to its knees after inside a few minutes.

   Rail stability was checked/measured with the CPUID Hardware monitor and a Metex multimeter which also recorded the system load in idle and in load. As always try to remember that the power consumption numbers listed in the graph are the highest (Peak) ones recorded during the entire duration of the tests and not the average ones. Noise levels coming from the fan were recorded using the high precision HD600 ExTech Sound dBA Meter from the rear of the unit and at a range of no more than 5-10cm. Readings under load are recorded the exact moment we manually switch the fans of all graphics cards from full speed to almost zero, that way the fan of the power supply does not have enough time to slow its RPM and so by doing this we get very accurate noise level readings. Needless to say, in order to get 100% accurate readings, you need to have a noise isolated room for that exact purpose, something which is quite impossible unless you are working inside a real lab (some people use very small noise insulated boxes but due to their size both heat and noise exceed normal levels and so the results can't really be considered to be 100% accurate, nor realistic for that matter). Also do take into account that since all noise measurements take place from just 5-10cm away the final noise levels to reach your ears will be considerably less.

* After well over 10 years of testing PSUs the Intel Core i7-920 CPU of this rig failed and was replaced it with a Xeon X5660 (also swapped the GA-X58A-UD7 for the G1. Assassin).

TEST RESULTS

CONCLUSION

   Three things are evident about the Seasonic Focus SPX-750 from today’s review, it’s high build quality (from interior components to the braided modular cables), solid rail stability and high noise levels. Both build quality and rail stability are things I’ve come to expect by a well-established company like Seasonic, noise levels however are not and so I can’t really figure out why they used such a high-speed fan (perhaps it’s the profile to blame and not so much the fan). As a matter of fact, the SPX-750 is probably the loudest power supply at full load to ever reach the lab (followed closely by the FSP Dagger Pro unit - although to be fair you’re not getting an 750W unit to max it out). Performance aside the fact that Seasonic makes the Focus SPX-750 available in both black and white colors is also a plus and will certainly be very popular among people with white cases and even hardware components.

   With a current price tag set at around USD190 inside the USA and 160Euros inside the EU the Focus SPX-750 SFX power supply unit by Seasonic is priced just a tad higher compared to other similar models. Still Seasonic is second to none to build quality and performance so that shouldn’t really be an issue for most people. The high noise levels on the other hand just might and that’s pretty much the only drawback of this specific model. Overall, however I simply can’t ignore everything else and since it delivers on rail stability (rock solid in my book), build quality (all but excellent), electrical efficiency (80 Plus Platinum) and looks (white version) it clearly deserves the Golden Award.

PROS

- Excellent Build Quality
- Tiny SFX Form Factor
- Rock Solid Rail Stability
- Up To 750W Continuous Output
- 80 Plus Platinum Certified
- 100% Japanese Capacitors
- Fully Modular
- Available In Black And White Colors
- 10 Year Limited Warranty

CONS

- Noise Levels
- Price (For Some)