Testing
The following system was used to test the cooler:
– Processor: Intel i9 9900K @ 5GHz
– Motherboard: ASRock Z390 Phantom Gaming X
– RAM: Ballistix Tactical Tracer 16GB DDR4 @ 2666MHz
– GPU: MSI GeForce RTX 2070 Super Gaming X Trio
– SSD: Crucial MX 500GB
– HDD: WD 1 TB Blue
– CPU Cooler: CoolerMaster MasterLiquid 240 with NoiseBlocker eLoop B12-PS
– Display: AOC i2769VM
– Case: Phanteks Enthoo Luxe White
– OS: Windows 10 64-bit
The above system has a power consumption of approximately 502W when in full load and 68W when idle, in order to test the efficiency of the Power Supply, the power draw of the system was measured at the wall socket. Also, the voltages were measured on the +12v +5v and +3.3v using a multi-meter.
To load the system to its maximum the stability test of the AIDA64 Extreme 6.25.5400 was used with Intel Burn Test V2.
The Power Supply was tested with the system both idle and at maximum load.
Power Supply efficiency
For rail voltage tolerance levels, ATX (Power Supply Design Guide) specify that a 5% variable fluctuation is acceptable.
Voltage oscillation idle
Voltage oscillation load
The noise level was measured at three different distances from the fans (10cm, 20cm, 30cm.) the noise was measured with a margin of error of ± 5 db.
Final thoughts
The Seasonic FOCUS GX-750 is available for around 120 USD or EUR, and for that it offers a good performance and a simple design that will be easy to match with any configuration.
The performance of the power supply is very good, this is mainly thanks to the excellent internal build quality and the usage of high-quality components. In terms of efficiency, the FOCUS GX-750 reached a maximum efficiency of 91.8% with a load of 500W.
The FOCUS GX-750 also has an internal wireless design, this is done to reduce the number of restrictions and allow the airflow to pass through all components.
The power supply is silent, the fan will not spin until the load reaches 30% of the total wattage capacity of the power supply. In addition, the fan operating modes can be changed by pressing the Hybrid mode button located at the back of the power supply. The power supply reached a peak of 30 decibels measured at the standard 10 centimeters from the system. The fan has no bearing noises or low pitch tones while spinning.
In conclusion, the Seasonic FOCUS GX-750 is a good power supply that improves on the already great Seasonic Focus series. The FOCUS GX-750 is available with a 10-year warranty, which shows the quality and performance of the improved Focus platform. The modular cables are flat and flexible, and all of them have a good length. The performance is good, both in terms of efficiency and voltage regulation.
Hold-up time FOR Seasonic Focus GX-750 ??
Unfortunately, at the moment, I cannot measure Hold-up time.
Hello !! Could you please tell me how many decibels reach at full load (500 watt) and not the average of idle and loa together ?? Thanks in advance !!
The load noise was around 33Db, could not even hear it.
This is a late reply, I know, mainly due to the fact I was looking up reviews for a possible second hand deal. The main issue is noise, but unfortunately this review does not understand noise at all.
First of all, the standard for measuring noise is at 1 meter away from the source. A reading from any other distance cannot be compared with anything else and is completely meaningless. Doesn’t even help comparing the listed models, because who is insane enough to listen to their power supply with their ear 10 cm away from the fan????? They can have vastly differing readings from 10cm, yet be completely silent from a 1m or longer distance, because the sound pressure quickly weakens when spreading as a sphere in all directions. If the PC is on the floor and you sit next to it on a chair, can you hear it AT ALL? If not, (or your super silent case fans are louder), then it doesn’t matter AT ALL. Decibel measurements are misleading, because few people understand the logarithmic nature of sound levels and decibels. Also they need to be highly accurate, which brings us the next problem.
A margin of error of +/- 5 dB??? Really? What have you measured with? That is a total difference of 10dB, which represents a DOUBLING of the sound level!! Anybody who is not completely deaf will hear much smaller differences than that… In plain English: of two psus with the same measured dB, one could in reality have double the noise level due to measurement error margin? How useful info is that? “This car has 100 horse power, but it could also be 50 due to measurement error”. “What about that car with 70?”. “Oh, it could actually have 140 hp?”
Hi Brian,
Thank you very much for your comment and information. You are correct in your statement, and I am working towards building a better testing methodology for reviewing power supplies.
The 1 meter distance has been used to highlight the worst case scenario: having your PC right next to you on the desk and quiet fans which allow the PSU to be audible. Is it the best way to measure noise for a PSU? Absolutely not, but at the time of the development of this methodology it was the best of both worlds. As many complained that if I measure the noise too close to the PSU, it’s not realistic as they are not sitting close to the PSU.
I appreciate the constructive criticism and I can assure you that I am working towards acquiring better equipment and developing a better testing system for PSU reviews.
Many thanks once again and I wish you have a good day ahead!
Thanks for taking my comment constructively. Sorry if I was a bit harsh, unfortunately I’ve read too many reviews that ignore realistic issues while splitting hairs on some irrelevant numbers (irrelevant because they are all well within specs). Also too many sites/magazines that only push whatever crap they get advertising money for. I think independent reviewers such as you do an important job by putting out more honest information and educate and help people choose smartly. Which is why I think correctness and relevance are so important.
The problem with giving numbers that look like they are exact and objective, but are not, is that people get fooled. They want simple answers to complex questions. Thus 2-3 dB less in a chart “is definitively better” even if they notice that the margin of error is 3x higher… They just want to know “which is the best”. Well, it depends on the needs, so then they go for the safe choice, which are the reviews or what everyone else thinks (if it is the wrong choice, at least they can blame someone else).
When it comes to sound measurements, it is a dilemma. Either it needs to be done scientifically according to standards with highly accurate (=pretty expensive) equipment in an anechoic chamber, or from a purely practical point of view which is more realistic, but far less accurate. The first option allows comparisons with similar tests (done to the same standards), but does not really translate into practice. Option 2 gives more useful info, but can’t be compared to other tests and then everybody’s setup is different. No matter how good scenarios you come up with, you will never satisfy everybody… But this approach would still give a reasonable idea of reality with a reasonable effort, as long as some common sense is used and it is accepted that it can’t be perfect. Maybe ask your readers where and how they keep their equipment and use that to cover most typical scenarios? Add some reviewers impressions to cover what measurements don’t tell. Maybe use measurements to help order the PSUs from silent to loud and/or group the PSUs under descriptive classes (e.g. silent, barely audible, clearly noticeable, disturbing, f..ing loud). Just don’t mislead readers with highly inaccurate numbers presented as facts. Yes, some will still want hard numbers, but spare them of selfdeception. A simple dB measurement (even if accurate) does not even tell if the noise is high or low frequency. Our ears are very sensitive to high pitch noices such as motor clicking or coil whine and much less to low pitch sounds, such as air flow. And while there are adjusted spl scales to try to compensate that, they can’t compensate for “irritation” factor. Example: I have stopped noticing our quite noisy AC, but that barely audible clicking sound that recently started on my current PSU drives me nuts! It even cuts throgh my earphones and I can’t concentrate if I need to think. Which is why I ended up on this site, looking for info on a cheap second hand PSUs for that 8 year old spare work PC (its cheaper to by a complete similar PC than a new PSU…)
Having now found this site, I’m looking forward to interesting reviews.
P.S. That “f..ing loud” is descriptive of an AcBel that came with an ASUS office computer. It was like a feaf blower even when running idle
As I’ve said previously, I am trying to develop a better way to not only test these power supplies but to measure their noise output. I’m thinking of measuring the noise output in two different locations to get a good average. Mamny issues are still present, such as ambient noise and of course, things that are out of my control such as coil whine.
“Having now found this site, I’m looking forward to interesting reviews” – Thank you!