NZXT launched its C850 SFX Gold in February 2026 with ATX 3.1 compliance and a native 600W 12V-2x6 cable, which signals how fast small-form-factor power supplies are catching up to full-size units. We could not find that model in stock on Amazon at publication, so the picks below are the SFX and SFX-L units that are. The shortlist runs from 750W for an RTX 5070 Ti-class build to 1000W for an RTX 5090 in a mini-ITX case, based on manufacturer specifications and published reviews.
| Spec | Corsair SF750 (2024) 9.2/10 | Corsair SF850 (2024) 9/10 | Corsair SF1000 (2024) 8.8/10 | Lian Li SP1000P 8.9/10 | ASUS ROG Loki SFX-L 750W 8.5/10 |
|---|---|---|---|---|---|
| wattage | 750W | 850W | 1000W | 1000W | 750W |
| form_factor | SFX (100 x 125 x 63.5mm) | SFX (100 x 125 x 63.5mm) | SFX (100 x 125 x 63.5mm) | SFX | SFX-L (125 x 63.5 x 125mm) |
| efficiency | 80 Plus Platinum / Cybenetics Platinum | 80 Plus Platinum / Cybenetics Platinum | 80 Plus Platinum / Cybenetics Platinum | 80 Plus Platinum | 80 Plus Platinum |
| standard | ATX 3.1 / PCIe 5.1 ready | ATX 3.1 / PCIe 5.1 ready (Corsair spec) | ATX 3.1 / PCIe 5.1 ready | ATX 3.1 / PCIe 5.1 | ATX 3.0 / PCIe 5.0 |
| fan | 92mm FDB, Zero RPM up to 300W | 92mm FDB, Zero RPM up to 340W | 92mm FDB, Zero RPM up to 400W | 92mm FDB, off at 40% load or below | 120mm Axial-tech, Zero RPM under 40% load |
| warranty | 7 years | 7 years | 7 years | 10 years | 10 years |
| Rating | 9.2/10 | 9/10 | 8.8/10 | 8.9/10 | 8.5/10 |
Prices change daily — tap Check Price for the current Amazon price.
Prices change daily — tap Check Price for the current Amazon price.
Quick Picks
- Best overall: the Corsair SF750 (2024) covers most mini-ITX gaming builds. It has a native 12V-2x6 cable, a fan that stays off up to 300W, and the standard 100mm SFX body.
- Best for a high-end GPU: the Corsair SF850 (2024) is the safer choice for an RTX 5080, and the Corsair SF1000 (2024) or Lian Li SP1000P suit an RTX 5090.
- Best warranty and SFX-L option: the Lian Li SP1000P carries 10 years, and the ASUS ROG Loki SFX-L 750W offers 10 years plus a larger 120mm fan if your case accepts SFX-L.
Buying Guide
SFX vs SFX-L vs ATX
A standard SFX power supply is 125mm wide, 63.5mm tall and 100mm deep. SFX-L keeps that footprint but is deeper, which is what lets it carry a 120mm fan instead of a 92mm one. Check your case spec sheet before buying: cases that list “SFX” only will reject an SFX-L unit, while cases that list “SFX / SFX-L” take either. Every unit in this guide ships with an SFX-to-ATX bracket, so each can also be mounted in a standard ATX case.
How many watts do you need?
SFF builds run hot, so efficiency and headroom matter more than in a roomy tower. As rough planning numbers, 750W suits cards up to the RTX 5070 Ti or RX 9070 XT, 850W suits an RTX 5080, and 1000W is the sensible choice for an RTX 5090 with a high-power CPU. Our small form factor GPU roundup lists which cards physically fit the smaller chassis, and the mini-ITX case roundup covers which of them take SFX versus SFX-L.
Connectors and standards
Modern GPUs use the 12V-2x6 connector. Every pick here includes a native cable, which matters in SFF cases because a bulky adapter plus a tight bend near the connector is a known cause of poor connections. ATX 3.1 adds stricter transient-load handling than ATX 3.0, which is why we flag the one pick sold under an ATX 3.0 label.
Fan size and noise
Compact units rely on a 92mm fan, and a 92mm fan has to spin faster than a 120mm fan to move the same air. Corsair’s SF line keeps its fan off up to 300W (SF750), 340W (SF850) and 400W (SF1000), so a typical 1440p gaming session on a mid-range card is quiet. Heavier loads are where the SFX-L ASUS unit’s larger fan helps. If you are also choosing a cooler for a cramped build, see the best low-profile CPU coolers.
Detailed Reviews
1. Corsair SF750 (2024)
The Corsair SF750 is the default recommendation for a mini-ITX gaming PC. It is rated 80 Plus Platinum and Cybenetics Platinum, meets ATX 3.1 and PCIe 5.1 requirements, and includes a roughly 400mm native 12V-2x6 cable. The 92mm fluid dynamic bearing fan stays off up to 300W of load.
At 750W, it runs an RTX 5070 Ti or RX 9070 XT build comfortably. It is tighter for an RTX 5080 plus a high-power CPU, which is where the SF850 comes in. The 7-year warranty is the shortest in this guide.
2. Corsair SF850 (2024)
The Corsair SF850 shares the SF750’s body, fan and cable design with 100W more capacity, and Corsair rates its fan to stay off up to 340W. That makes it the better match for an RTX 5080 where a 750W unit would run near its limit.
One buying note: Amazon carries several SF850 listings, and the one linked here is titled ATX 3.0 compliant. Corsair specifies the 2024 line as ATX 3.1, so check the listing title if that certification is a must-have.
3. Corsair SF1000 (2024)
The Corsair SF1000 is one of the few 1000W units that still fits a standard SFX bay. That matters for RTX 5090 builds in cases like the ones in our under-$100 mini-ITX case guide, where an SFX-L unit will not fit. Zero RPM mode works up to 400W of load.
The trade-off is fan effort: a 92mm fan at 1000W has to work harder than a larger fan would, so expect it to be audible under sustained full load.
4. Lian Li SP1000P
The Lian Li SP1000P is a 1000W SFX unit with 80 Plus Platinum, ATX 3.1 and PCIe 5.1 compliance, and a 10-year warranty. Its 92mm FDB fan is off at 40% load or below, and it ships with a reinforced 600W 12V-2x6 cable, an SFX-to-ATX bracket and an extension cord with an inline switch.
The spec sheet lists about 45 dBA at full load, so it is a capable option rather than a silent one. Choose it over the SF1000 if the longer warranty matters.
5. ASUS ROG Loki SFX-L 750W
The ASUS ROG Loki SFX-L 750W measures 125 x 63.5 x 125mm and carries a 120mm fan that stays off below 40% load. It is 80 Plus Platinum, fully modular, and has a 10-year warranty plus a 600W PCIe Gen 5 cable.
It only fits cases that accept SFX-L, and the Amazon listing is labeled ATX 3.0, so pick it for the larger fan and warranty rather than the newest standard. The fan includes addressable RGB.
FAQ
Can I use an SFX power supply in an ATX case?
Yes. All five units here include an SFX-to-ATX bracket, so they mount in a standard ATX case. The reverse is not true: an ATX unit will not fit an SFX bay.
Is 750W enough for an RTX 5080?
It can work on paper, but 850W gives more headroom for transient spikes and a higher-power CPU. In a cramped SFF case, where airflow is limited, that extra headroom also keeps the unit out of its louder fan range.
What is the difference between SFX and SFX-L?
SFX-L is longer, at 125mm against 100mm, which allows a 120mm fan. Check your case listing, since SFX-only cases cannot take it.
Do I need ATX 3.1?
It is not mandatory for a working build, but ATX 3.1 tightens transient-load handling for high-power GPUs, so it is worth preferring on new purchases. For larger cases, see our best 850W power supplies and best 1000W power supplies.
The Bottom Line
For most small builds, buy the Corsair SF750; step up to the Corsair SF850 for an RTX 5080. For an RTX 5090, take the Lian Li SP1000P if you want the 10-year warranty, or the Corsair SF1000 for its proven SF platform. If your case accepts SFX-L, the ASUS ROG Loki SFX-L 750W adds a larger, slower fan. For the full build workflow, see our small form factor PC build guide.