Corsair SF1000 Platinum (2024) PSU Review

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

To see our review of the Corsair SF850 Platinum (2024) click HERE.

Today we look at something rather unusual and exciting – one of the smallest 1000 Watt power supplies I have ever seen. This unit measures only 100mm x 125mm x 63.5mm so will fit into even the smallest chassis on the market today. Corsair have updated this platform to the latest ATX 3.1 standards, and it is a fully modular Platinum rated power supply with a 7 year warranty.

Previously, Corsair had their Gold certified SF1000L on the market, so for this new version Corsair have improved efficiency levels while making the power supply smaller. On paper this is some achievement, so we can't wait to see how it holds up in our testing later in the review.

• Cybenetics Platinum Rated SFX Power: Massive Platinum-rated power in a compact SFX form-factor, perfect for the most power-dense small-form-factor PCs or saving space in larger cases.
• ATX 3.1 Compliant & PCIe 5.1 Ready: Compliant with the ATX 3.1 power standard from Intel®, supporting the PCIe Gen 5 platform and resisting transient power spikes.
• Fully Modular, Type-5 Micro-Fit PSU Connectors: With flexible cabling, taking up less space for tidy cable management and compatibility in small cases.
• 92mm PWM Cooling Fan: Delivers powerful cooling with low-noise operation thanks to a fluid dynamic bearing.
• 105°C Rated Japanese Capacitors: For unwavering power and reliability. 6. Zero RPM Mode: The fan stays off until it’s needed, for near-silent operation at low and medium loads.
• 50°C Continuous Operating Temperature: For reliable power even under high-stress conditions.
• SFX-to-ATX Bracket Included: Enables installation into ATX cases for more cable space in larger systems.
• Seven-Year Warranty: For complete peace of mind.

The box artwork for the SF1000 is pretty traditional for Corsair. It ships in a bright yellow box with a high resolution image of the unit on the front. This power supply also achieves the Cybenetics Platinum rating which. in 2024, seems to be worth a lot more than the traditional 80 Plus ratings.

The rear of the box highlights some of the key features along with some informational graphs on efficiency levels and noise.

The box is split into two compartments. One side of the box is home to the PSU itself. The other side contains the extras, including the modular cabling.

Corsair include some literature on the PSU, some cable ties, mounting screws and an ATX adapter bracket, if needed.

The modular cables are high quality, individually sleeved and look great.

The cables are long enough for usage in smaller chassis.

The Corsair SF1000 is a really small power supply measuring only 125mm x 100mm x 63.5mm (WxHxD). It is finished to a high standard and is neutral by colour, all black with accents of silver/white on the lettering.

To give you an idea of just how small this unit is – you can see it above, resting on the Antec HCG1000 unit we reviewed recently.

One side of the unit is home to the power connector and switch, alongside a vented panel to aid airflow.

The other side houses the modular bay, split into three rows, all labelled for ease of use during the install phase.

The power sticker shows that the unit can deliver 83.3A to the +12V rail, along with 20A to both minor +3.3V and +5V rails. Corsair have removed the -12V rail from this PSU which helps increase efficiency and remove some costs. This rail is not really needed in 2024 so there is no problem.

Corsair are using an NR092P fan, rated 0.22A 12V. This is a good quality FDB (fluid dynamic bearing) fan which we have seen several times in the past. There are no plastic strips on this unit to direct air flow to specific parts – it is just left stock.

This unit is a Great Wall OEM part, like some previous Corsair designs. The PCB is tiny as you can see in the images above and very heavily packed. The build quality looks very good to me and soldering quality on the PCB is excellent.

It is a half bridge topology design and an LLC resonant converter increases the efficiency levels via lossless switching. On the secondary side a synchronous rectification adopts eight FETs to regulate the 12V rail. As usual, the minor rails are generation via a pair of DC-DC converters via a PWM controller.

The primary stage capacitor is a 105c Rated Rubycon rated at 420V 740uF. These are quality Japanese capacitors we value highly, alongside others such as Nippon Chemi Con and Nichicon. The power supply offers OCP, OVP, SCP, OPP and OTP 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	3.33	0.90	5.01	7.35	12.04	0.50	5.01	0.20	-12.01
200W	1.60	3.33	1.64	5.01	15.13	12.04	1.00	5.01	0.20	-12.01
500W	3.21	3.33	3.24	5.01	38.60	12.04	1.50	5.01	0.20	-12.01
750W	4.03	3.33	4.17	5.01	58.53	12.03	2.00	5.01	0.30	-12.00
1000W	5.45	3.33	5.51	5.01	78.13	12.02	2.50	5.01	0.30	-12.02

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

Corsair SF1000 PSU	Maximum Load
	1111W

The power supply managed to deliver 1111W 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	12.02	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

This power supply 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	13	16	15	17
250W	15	16	22	18
500W	16	18	27	19
750W	18	19	31	23
1000W	21	21	35	25

Noise suppression is not class leading, but pretty good and well within industry rated safe parameters.

Efficiency (%)
100W	89.7
250W	92.5
500W	94.1
750W	92.7
1000W	89.9

The efficiency results are really good, achieving Platinum rated efficiency levels, peaking at just over 94% between 45-55% load, and dropping to around 90% at full load.

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	33.2
750W	36.8
1000W	38.9

The high quality FDB fan is not very noticeable until load hits around 700 Watts demand – then you can hear it ramping up. It is a pretty small fan, so usually noise levels are inherently higher. It's not the quietest unit we have tested, but I would not call noise levels excessive either. Such a small physical footprint always comes with some trade off.

Temperature (c)
	Intake	Exhaust
100W	37	41
250W	38	45
500W	40	52
750W	45	57
1000W	46	60

The large fan and high levels of efficiency ensure good airflow across the components and good operating temperatures.

Maximum load	Efficiency
1111W	89.0

Pushing the PSU above its rated limits generates an efficiency of around 89.0. Not a practical situation in the real world of course.

The Corsair SF1000 is not only the best SFX power supply I have ever tested, it is also one of the finest power supplies on the market today. Corsair's partnership with Great Wall is reaping dividends – Corsair can confidently claim that for the small form factor market, this is the ultimate PSU you can currently buy.

The Corsair SF1000 excels in a wide array of tests, with only ripple suppression falling inside parameters we would label as good, rather than exceptional. It is not a concern however, as the results are still well within industry rated parameters.

Load regulation scores well and the unit achieved 80 Plus Platinum levels, and considering the small form factor and overall performance, it is difficult to not be impressed by these results today. It is also important to note that this unit also achieves Platinum approval from Cybenetics and really everyone should value them more now than the dated, somewhat dubious 80 Plus ratings.

SF1000 noise emissions are relatively decent until the upper end of power delivery. This is not the quietest power supply you can buy, however this is always going to be a trade off with a small physical unit incorporating a 92mm fan, rather than 120mm or 135mm equivalent. A smaller fan at any given speed – if quality is consistent between the models – will always generate slightly more noise than a larger fan. It is unavoidable.

Right now you can pick up this power supply from SCAN in the UK for £199.99 HERE. I consider it a good value purchase as it targets a market which sometimes gets overlooked by other brands.

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Pros:

• Delivered a sustained 1100W.
• High quality design from soldering to components.
• 105C Japanese capacitors.
• Stellar build quality.
• Tight load regulation.
• FDB fan is great.
• 7 year warranty.
• Compact design suits many builds.
• Quality cabling.
• Fully modular.
• ATX 3.1/PCIe 5.1.
• SFX to ATX adapter bracket in box.

Cons:

• Not the quietest power supply under load.

KitGuru says: The SF1000 Platinum power supply is one of the finest we have tested, and is without question the best SFX power supply on the market today. It delivers huge levels of power, with high levels of efficiency and stellar build quality. It earns our highest award today.

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