Seasonic Focus GX-1000 V4 (2024) ATX 3 Review

1. Introduction2. Bundle & Cabling3. External4. Internal5. Testing Methodology and Results6. Closing Thoughts7. View All Pages

Seasonic have just updated their Focus GX range of power supplies for 2024 and today we take a look at the new GX-1000 model. This time the company are placing a lot of focus (sorry) on their new OptiSink technology. This range of ATX power supplies is compact in size (140mm deep), 80 Plus Gold rated and fully modular. They are also available in black or white and the company offer a full 10 year warranty for peace of mind.

The new Seasonic Focus GX range adopts OptiSink technology, which is the implementation of automated surface mount technology on a new PCB layout, along with the use of smaller MOSFET and heat sinks components to increase the internal space within the PSU. Seasonic claim this enhancement improves airflow and makes the new Focus GX (2024) series more efficient therefore improving the overall quality and reliability. I will look at this more later on the review.

Focus GX (2024) ATX 3 – Feature Summary:

• 80 PLUS® Gold efficiency
• Available Power Output: 1000 W, 850 W and 750 W
• ATX 3 and 16-Pin PCIe Gen 5 Cable (12-2×6)
• Compact Size: 140 mm
• Seasonic Hybrid Silent Fan Control
• Protection Features: OPP / OVP / UVP / SCP / OCP / OTP
• 10-year warranty

The Focus GX-1000 box doesn't have any images of the PSU itself on the front – there are just some key selling points, including the 80 Plus Gold sticker, the 10 year warranty, hybrid fan control, modular configuration, and ATX 3 / PCIe 5 compliance.

The rear of the box lists out key features across two sections with a graph highlighting the efficiency ratings.

The box contains some literature on the product, as well as cable ties and a PSU tester. They also supply a regional specific power cable. Seasonic wrap up all the modular cables in a bag.

The modular cables are high quality and individually sleeved. The updated 12V-2×6 cable is 16 AWG gauge with a maximum rated power of 600 Watts.

The length of the cables are good, with the main CPU cable 700mm long. The MB connector is 610mm long which is fine for a variety of cases.

Seasonic sell both black and white versions of these power supplies. Leo was sent a white one for video content, I received a black version. This power supply is classified by Seasonic internally as a ‘small footprint' model, with a depth of 140mm. The PRIME, PRIME Fanless and VERTEX are longer.

The large fan is hidden behind a very fancy grill design. We will take a closer look at the fan when we open the chassis.

The modular bay is split across two rows with clearly labelled sections highlighting the sections.

The other side of the chassis has a power connection, a power switch and a hybrid fan mode button.

This 1000 Watt unit is able to deliver 83A via the +12V rail for 996W of the total power output. Seasonic have set the minor +3.3V and +5V rails at 25A.

Seasonic power supplies in recent years always seem to ship with Hong Hua fans and this one is no different. They are using a high grade HA13525H12F-Z fluid dynamic bearing fan rated at 2000 rpm, 0.50A, 12VDC. We have seen this fan way back in 2018 and it even featured in Antec units with Seasonic as the OEM (HCG Extreme Series 1000W).

You can buy these fans directly from Asia for around $25, so it's 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 have a small plastic strip running along the right side in the image above – this is a technique used to specifically direct air flow over the most sensitive components underneath.

Seasonic do not rely on a third party OEM for their designs – they design in-house. They have made many power supplies for companies such as Antec, Phanteks and ASUS.

The primary stage of this power supply adopts a single 105C rated Japanese capacitor from Nippon Chemi Con, a brand we see in Seasonic power supplies all the time. This primary capacitor is rated 400v 820uF. The last generation Focus GX-1000 that we reviewed back in September 2023 used two capacitors from Nippon Chemi Con, at 560uF and 330uF respectively for the same total output of 890uF. The secondary stage also features high grade Japanese capacitors. This unit offers OPP, OVP, UVP, OCP, OTP and SCP protections. As mentioned earlier there is a 10 year warranty with this power supply. This is only 2 less than the higher cost PRIME and VERTEX units in the range.

Seasonic have altered the design of this power supply, implementing surface mount technology on a new PCB layout. This helps to increase the internal space within the PSU, helping to enhance airflow and cooling performance.

The MOSFET daughter board is placed near the casing to improve heat transfer to the chassis itself.

Seasonic sent us a diagram of a Heat Transfer Coefficient which explains that the thermal conductivity of any given material is a measure of its ability to conduct heat. This is commonly denoted by ‘k' and is measured in W/m.K (Watts/meter-kelvin). Therefore the higher the value of k, the greater the materials ability to conduct heat.

We reviewed the previous generation of the Focus GX-1000 more than a year ago (HERE). If you want to compare internal shots and see the new design for yourself, our last review has a breakdown page over HERE. The platform density has changed from 36030mm³ to 17383 mm³.

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	3.33	0.90	5.02	7.35	12.03	0.50	5.01	0.20	-12.01
200W	1.60	3.33	1.64	5.02	15.13	12.03	1.00	5.01	0.20	-12.01
500W	3.21	3.33	3.24	5.02	38.60	12.02	1.50	5.00	0.20	-12.02
750W	4.03	3.33	4.17	5.02	58.53	12.02	2.00	5.01	0.30	-12.02
1000W	5.45	3.33	5.51	5.01	78.13	12.00	2.50	5.00	0.30	-12.01

The load regulation of this power supply is excellent across the board.

Seasonic Focus GX-1000	Maximum Load
	1148W

The power supply managed to deliver 1148W 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	3.33	2.0	5.01	72.0	12.03	0.2	-12.01	0.50	5.01
240W	20.0	3.33	23.0	5.01	2.0	12.03	0.2	-12.01	0.50	5.01

The GX-1000 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	4	6	7	4
250W	4	7	7	4
500W	6	9	9	5
750W	8	10	13	6
1000W	10	11	15	7

Ripple noise suppression is superb, with the primary +12V rail peaking at 15mV at full load. Secondary +3.3V and +5V rails both peak around 10mV at full load.

Efficiency (%)
100W	89.2
250W	90.7
500W	93.1
750W	92.0
1000W	90.4

The efficiency results are excellent, peaking at 93% at around 45% load. This drops to around 90.4% 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	31.8
750W	33.4
1000W	35.2

The fan remains relatively quiet throughout the range, picking up some speed at around 700 Watt load, when it becomes more audible. This new power supply design seems a little quieter than the previous 2023 model.

Temperature (c)
	Intake	Exhaust
100W	37	41
250W	38	46
500W	40	50
750W	45	53
1000W	46	58

The fan ramps up in the last 300 Watt of load output, ensuring good airflow across the components. The new OptiSink configuration delivers good results overall.

Maximum load	Efficiency
1148W	88.6

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 should look at a 1600W unit such as the excellent Seasonic Prime TX-1600 (review HERE) or even the Enermax Revolution D.F.X. 1650W model (review HERE)

Seasonic have been my personal ‘go to' for power supplies for some time. I review a lot of PSUs and I have great success with Seasonic over the years. They are reliable and use the highest grade components inside.

This new Focus GX-1000 V4 for 2024 follows on from the previous 2023 model which scored very well in our tests last September. Seasonic are trying to refine and improve this design by adopting automated surface mount technology on a new PCB layout, as well as using smaller MOSFET and heat sink components to help improve airflow. This means when under very heavy loads the components should be running cooler and quieter.

As before, this is a very capable power supply exhibiting no major weakness in any area. Load regulation is tight and the unit coped with the cross load test without any concerns.  Seasonic always use quality $25 Hong Hua Fluid Dynamic bearing fans in this range of supply so when combined with the high grade 105C-rated Japanese Nippon Chemi Con capacitors and 10 year warranty, you know it is going to last many years.

Like the previous model, the power supply is over-specced for the 1000 Watt rating and it delivers high levels of efficiency – around 93% in our testing. Thankfully Seasonic have maintained the small 140mm deep physical footprint so it is well suited to a huge variety of chassis designs.

Seasonic now offer these new Focus GX power supplies in both black and white and while UK pricing is to be confirmed we have the following direct from Seasonic. The white versions of these power supplies are $10 more expensive than the white versions, so if your power supply is hidden from view it makes more sense to opt for black.

Pricing for the range is as follows:

• FOCUS GX-750: $ 129.99 (USA) / 119.90€ (Europe) / $119.99 (ROW)
• FOCUS GX-850: $149.99 (USA) / 139.90€ (Europe) / $139.99 (ROW)
• FOCUS GX-1000: $189.99 (USA) / 169.90€ (Europe) / $169.99 (ROW)

• FOCUS GX-750 White: $139.99 (USA) / 129.90€ (Europe) / $129.99 (ROW)
• FOCUS GX-850 White: $159.99 (USA) / 149.90€ (Europe) / $149.99 (ROW)
• FOCUS GX-1000 White: $199.99 (USA) / 199.90€ (Europe) / $179.99 (ROW)

Pros:

• Exceeds 80 Plus Gold rating.
• 105C-rated Japanese capacitors from Nippon Chemi Con.
• Low noise levels.
• Fully modular.
• 10 year warranty.
• Load regulation is tight.
• 140mm footprint.
• Quieter than previous designs.
• Cooler than previous designs.
• Lovely individually sleeved cables.

Cons:

• None.

KitGuru says: With the new range of Focus GX units for 2024 Seasonic have streamlined and enhanced the previous design from last year. This is a power supply that should be seriously considered if you have a high power PC and you have a budget around the $170-$180 mark.

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