![](https://www.kitguru.net/wp-content/uploads/2023/09/650px2-310x165.jpg)
Seasonic have cemented their position in the market over the last decade as one of the world's leading power supply brands. Recently they launched a range of new Focus GX units, in 750W, 850W and 1000W capacities. These new 80 Plus Gold units target the mainstream enthusiast audience, offering competitive pricing and a list of features set to tick a long list of boxes.
These new GX power supplies are all fully modular, with a small 140mm physical footprint to fit in a variety of chassis designs. Seasonic have adopted high grade Japanese capacitors throughout, along with a Fluid Dynamic Bearing fan for long life. Seasonic back these units up with a 10 year warranty, for peace of mind.
The MSRP for the three power supplies in the range is:
FOCUS GX-750 ATX 3.0: 129.90€ / 119.99£.
FOCUS GX-850 ATX 3.0: 149.90€ / 149.99£.
FOCUS GX-1000 ATX: 3.0: 199.90€ / 179.99£.
Features overview:
- ATX 3.0 and PCIe 5.0 Cable (12VHPWR)
- 80 PLUS® Gold certified
- Compact Size – 140 mm deep
- Top-Quality 135 mm FDB Fan
- Digital Hybrid Fan Control
- S3FC – Fanless until 30 % load
- Cable-free Connection Design
- Tight Voltage Regulation
- Gold plated connectors
- 10 years warranty
The Focus GX-1000 power supply ships in a bright gold coloured box with no image of the unit on the front – just a list of key specifications along with the 10 year warranty.
The rear of the box is mainly focused around an efficiency graph with some information on key features of the power supply.
Inside the box are some cable ties, literature on the unit, a regional specific power cable, mounting screws and a PSU tester. The PSU itself is wrapped in a protective cover.
The cables supplied in the box are all individual sleeved and look fantastic. Ideal for a custom build where they are on show. Seasonic even show how they advise the 12VHPWR CABLE to be installed. The 1000 Watt supply has plenty of cables for a high end system build.
The Focus range of power supplies ship in plain black, unlike the Prime range of units which are accented with silver panels. Likely not even a consideration for most people in 2023, as power supplies tend to be installed behind shrouds and case panels.
The fan is hidden behind the grille along the top – we will take a look at the specific model Seasonic use a little later.
The modular bay is clearly laid out across two rows, labelled for ease of use during the build phase. The other side of the power supply is home to the power connector socket, button and hybrid fan mode button – to keep the fans silent at lower load levels.
The 1000W unit is able to deliver 83A to the single +12V rail, with 25A to both +3.3V and +5V output.
Seasonic are using a 135mm Hong Hua Fan, marked HA13525H12F-Z. This brand feature in all of the Seasonic power supplies we have tested in the last 1-2 years. It is an excellent Fluid Dynamic bearing fan with a long life span and relatively low noise output If kept below 2,000 rpm. It is rated 0.50A 12VDC with a maximum rotational speed of 2,300 rpm.
Seasonic have a small plastic panel attached over the fan (see above) to specifically direct air flow to the components underneath. Incidentally you can buy these fans directly from ASIA for around $25, so its a relatively expensive unit. We have even seen them listed on EBAY lately (HERE). The fan is rated to a 100,000 hours mean time before failure @ 25c.
Seasonic don't rely on any OEM partner for their designs. All their units are created in house. Sometimes you will find Seasonic designs in other companies power supplies such as Corsair, ASUS and Phanteks.
The primary stage of this design adopts two 105c rated capacitors from Nippon Chemi Con (KMR) and Nichicon – two very highly regarded Japanese brands.They are rated 560uf and 330uf respectively for a total output of 890uf. The secondary stage also features high grade Japanese capacitors.
The unit offers OPP, OVP, UVP, OCP, OTP and SCP protections.
Correctly testing power supplies is a complex procedure and KitGuru have configured a test bench which can deliver up to a 2,000 watt DC load.
We test ambient temperatures at 35c in our environment to greater reflect warmer internal chassis conditions.
We use combinations of the following hardware:
• SunMoon SM-268
• CSI3710A Programmable DC load (+3.3V and +5V outputs)
• CSI3711A Programmable DC load (+12V1, +12V2, +12V3, and +12V4)
• Extech Power Analyzer
• Extech MultiMaster MM570 digital multimeter
• SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa)
• Digital oscilloscope (20M S/s with 12 Bit ADC)
• Variable Autotransformer, 1.4 KVA
We test in a single +12V configuration.
DC Output Load Regulation
|
||||||||||
Combined DC Load |
+3.3V
|
+5V
|
+12V
|
+5VSB
|
-12V | |||||
A
|
V
|
A
|
V
|
A
|
V
|
A
|
V
|
A | V | |
100W
|
0.90
|
3.34
|
0.90
|
5.01
|
7.35
|
12.07
|
0.50
|
5.01
|
0.20
|
-12.00
|
200W
|
1.60
|
3.34
|
1.64
|
5.01
|
15.13
|
12.05
|
1.00
|
5.01
|
0.20
|
-12.01
|
500W
|
3.21
|
3.34
|
3.24
|
5.01
|
38.60
|
12.03
|
1.50
|
5.01
|
0.20
|
-12.01
|
750W |
4.03
|
3.34
|
4.17
|
5.01
|
58.53
|
12.01
|
2.00
|
5.01
|
0.30
|
-12.01
|
1000W
|
5.45
|
3.33
|
5.51
|
5.01
|
78.13
|
11.99
|
2.50
|
5.00
|
0.30
|
-12.00
|
The load regulation of this power supply is excellent across the board.
Seasonic Focus GX-1000 | Maximum Load |
1145W |
The power supply managed to deliver 1145W before shutting down safely.
Next we want to try Cross Loading. This basically means loads which are not balanced. If a PC for instance needs 500W on the +12V outputs but something like 30W via the combined 3.3V and +5V outputs then the voltage regulation can fluctuate badly.
Cross Load Testing | +3.3V | +5V | +12V | -12V | +5VSB | |||||
A | V | A | V | A | V | A | V | A | V | |
885W | 2.0 | 3.34 | 2.0 | 5.01 | 72.0 | 12.01 | 0.2 | -12.01 | 0.50 | 5.01 |
240W | 20.0 | 3.32 | 23.0 | 5.00 | 2.0 | 12.06 | 0.2 | -12.00 | 0.50 | 5.00 |
The GX1000 handled our cross load test very well, holding stable results across the range.
We then used an oscilloscope to measure AC ripple and noise present on the DC outputs. We set the oscilloscope time base to check for AC ripple at both high and low ends of the spectrum. ATX12V V2.2 specification for DC output ripple and noise is defined in the ATX 12V power supply design guide.
ATX12V Ver 2.2 Noise/Ripple Tolerance
|
|
Output
|
Ripple (mV p-p)
|
+3.3V
|
50
|
+5V
|
50
|
+12V1
|
120
|
+12V2
|
120
|
-12V
|
120
|
+5VSB
|
50
|
Obviously when measuring AC noise and ripple on the DC outputs, the cleaner (less recorded) means we have a better end result. We measured this AC signal amplitude to see how closely the unit complied with the ATX standard.
AC Ripple (mV p-p) | ||||
DC Load | +3.3V | +5V | +12V | 5VSB |
100W | 5 | 5 | 5 | 5 |
250W | 5 | 5 | 5 | 5 |
500W | 5 | 5 | 10 | 5 |
750W | 5 | 10 | 15 | 5 |
1000W | 10 | 10 | 20 | 5 |
Ripple noise suppression is superb, with the primary +12V rail peaking at 20mV at full load. Secondary +3.3V and +5V rails both peak around 10mV at full load.
Efficiency (%)
|
|
100W
|
89.1
|
250W
|
90.4
|
500W
|
92.8
|
750W
|
91.9
|
1000W
|
90.2
|
The efficiency results are excellent, peaking at 92.8% at around 45% load. This drops to around 90.2% efficiency at full load. These are really very positive results for an 80 Plus Gold rated unit.
We take the issue of noise very seriously at KitGuru and this is why we have built a special home brew system as a reference point when we test noise levels of various components. Why do this? Well this means we can eliminate secondary noise pollution in the test room and concentrate on components we are testing. It also brings us slightly closer to industry standards, such as DIN 45635.
Today to test the Power Supply we have taken it into our acoustics room environment and have set our SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa) one meter away from the unit. We have no other fans running so we can effectively measure just the noise from the unit itself.
As this can be a little confusing for people, here are various dBa ratings in with real world situations to help describe the various levels.
KitGuru noise guide
10dBA – Normal Breathing/Rustling Leaves
20-25dBA – Whisper
30dBA – High Quality Computer fan
40dBA – A Bubbling Brook, or a Refrigerator
50dBA – Normal Conversation
60dBA – Laughter
70dBA – Vacuum Cleaner or Hairdryer
80dBA – City Traffic or a Garbage Disposal
90dBA – Motorcycle or Lawnmower
100dBA – MP3 Player at maximum output
110dBA – Orchestra
120dBA – Front row rock concert/Jet Engine
130dBA – Threshold of Pain
140dBA – Military Jet takeoff/Gunshot (close range)
160dBA – Instant Perforation of eardrum
Noise (dBA)
|
|
100W
|
<28.0
|
250W
|
<28.0
|
500W
|
32.4
|
750W
|
34.9
|
1000W | 36.4 |
The fan remains relatively quiet throughout the range, picking up some speed at around 700 watt load, when it becomes more audible. At full load the fan can be heard but it never becomes too intrusive.
Temperature (c)
|
||
Intake
|
Exhaust
|
|
100W
|
37
|
41
|
250W
|
38
|
45
|
500W
|
40
|
53
|
750W
|
45
|
54
|
1000W
|
46
|
61
|
The fan ramps up in the last 300 watt of load output, ensuring good airflow across the components. The fan profile is balanced, combining reasonable acoustics with good internal airflow.
Maximum load
|
Efficiency
|
1145W
|
88.4
|
Pushing the PSU above its rated limits generates an efficiency of around 88.4. Not a practical situation in the real world of course. If you need 1145 watts on a regular basis, you would need to look at a 1600W unit such as the excellent Seasonic Prime TX-1600 (review HERE).
In recent months Seasonic have released some fantastic power supplies in the high end sector – such as the Titanium rated Prime TX-1600 (review HERE). Having a more affordable range of units is critical to maintaining market share, and this is exactly where the new FOCUS 80 Plus Gold range fit in.
The FOCUS GX-1000 is a very capable power supply that exhibits no major weakness in any area. Load regulation is tight and the unit coped with the cross load test without any issues. The adoption of a high grade Fluid dynamic bearing fan and 105c rated Japanese capacitors will ensure long term reliability.
Ripple suppression rates highly, with +12V peaking at 20mV at full load, while both secondary +3.3V and +5V rails peak at 10mV. These are at the top of the class in regards to Gold rated units we have tested in recent years.
The unit achieved both 80 Plus Gold rated certification in our tests as well as delivering almost 1,150 Watts before shutting down safely. This is an overspec'd unit that will handle 1000 watts load for many hours if required. Obviously if you need 1000 watts output for any length of time we would recommend something like the aforementioned Prime TX 1600, as efficiency levels and noise output would be much lower, and less strain would be placed on the capacitors.
Noise output on this unit is quite low and never intrusive due to the excellent Hong Hua FDB fan. The fully modular design and small physical footprint (140mm) will ensure this unit will fit into a vast myriad of chassis designs without routing issues. Seasonic also back this unit up with a 10 year warranty for peace of mind.
Pricing is competitive. The GX-750 unit is targeted at £119.99, the GX-850 at £149.99 and this flagship GX-1000 is priced at £179.99. Just be sure to get this latest ATX 3.0 model with an EAN of 4711173878049.
Pros:
- Exceeds 80 Plus Gold rating.
- 105c rated Japanese capacitors from Nichicon and Nippon Chemi Con.
- low noise levels.
- fully modular.
- 10 year warranty.
- load regulation is tight.
- 140mm footprint.
- lovely individually sleeved cables.
Cons:
- None.
KitGuru says: One of the best 1000 watt 80 Plus Gold rated power supplies we have tested. It delivers quality power well in excess of 1000 watts without making too much noise. The internal design is top drawer and adopts high grade 105c rated Japanese capacitors to ensure long life and reliability during high draw sustained load environments. The 10 year warranty offers extended peace of mind.