CORSAIR SF850 (2024) Fully Modular Low Noise 80 Plus Platinum ATX Power Supply – ATX 3.1 Compliant – PCIe 5.1 Ready – SFX-to-ATX Bracket Included – Black
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An 850-watt, 80 PLUS Platinum SFX power supply with ATX 3.1 compliance and PCIe 5.1 readiness for compact, high-performance PC builds.
This 850W SFX power supply is specifically designed for compact, high-performance SFF PCs, offering ATX 3.1 and PCIe 5.1 compliance for modern hardware. Its fully modular design and included SFX-to-ATX bracket enhance its adaptability for various small builds.
If 850W isn't enough for your high-end components or you need more space for cables, consider an SFX-L or full ATX power supply with a higher wattage rating.
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Pros
- Delivers 850 watts of 80 PLUS Platinum-rated power in a compact SFX form-factor.
- Compliant with ATX 3.1 power standard and PCIe 5.1 ready, including a 12V-2x6 GPU cable.
- Features fully modular, Type-5 Micro-Fit PSU connectors for flexible cabling and tidy management.
- Equipped with a 92mm PWM cooling fan that operates with Zero RPM Mode at low to medium loads.
- Built with 105°C rated Japanese capacitors for power delivery and a 7-year warranty.
Cons
- The price point is higher compared to some other power supplies.
- Some users report included cables are shorter, potentially complicating cable management in larger cases.
- The new Type-5 connectors can be a hassle for users seeking compatible custom cables.
- The 92mm fan can reach 2800 RPM at full load, generating audible noise.
- A few users experienced their included 12VHPWR cable causing GPU crashes.
Dimension Scores
Achieves 80 PLUS Platinum efficiency and delivers 850 watts, compliant with ATX 3.1 and PCIe 5.1 standards, and built with 105°C rated Japanese capacitors.
Features a 92mm PWM fan with Zero RPM Mode for silent operation at low loads, but the fan can reach 2800 RPM under full load, generating noise.
Constructed with 100% industrial-grade, 105°C rated Japanese electrolytic capacitors and backed by a 7-year warranty, indicating a focus on longevity.
Offers a fully modular design with Type-5 Micro-Fit connectors and flexible cabling for reduced clutter, though some users find the cable lengths short for larger cases.
Best For
- Small form-factor (SFF) PC builds requiring 850W of power.
- Systems utilizing modern, power-hungry GPUs that need ATX 3.1 and PCIe 5.1 support.
- Users prioritizing space-saving components without sacrificing power efficiency.
Not Recommended For
- Budget-focused PC builds where cost is the primary concern.
- Users with larger ATX cases who need longer native cable runs.
- Anyone highly sensitive to fan noise under sustained high loads.
Watch Out For
- Cable length issues have been reported, making routing difficult in cases larger than SFF, potentially requiring extensions.
- Some customers received units with packaging stating 'ATX 3.0' despite ordering the 2024 'ATX 3.1' model, though Corsair states these are 3.1 certified.
- A few users experienced GPU crashes when using the included 12VHPWR cable, necessitating a return to GPU-provided adapters.
- The Zero RPM fan mode might not activate as expected for some users, leading to concerns about fan operation at low loads.
- An initial minor electrical smell has been noted by some users, which is expected to dissipate over time.
Full Specifications
| ASIN | B0D45PQ8C4 |
| Brand | Corsair |
| Color | Black |
| Series | SF850 |
| Wattage | 850 watts |
| Model Name | SF850 |
| Form Factor | SFX |
| Item Weight | 2.31 pounds |
| Manufacturer | Corsair |
| Connector Type | ATX |
| Cooling Method | Air |
| Output Wattage | 850.0 |
| Item model number | CP-9020256-NA |
| Compatible Devices | Monitor |
| Product Dimensions | 4.92 x 3.94 x 2.5 inches |
| Item Dimensions LxWxH | 4.92 x 3.94 x 2.5 inches |
| Item dimensions L x W x H | 4.92 x 3.94 x 2.5 inches |
What Buyers Say
Many users are impressed by how much power Corsair packed into this small SFX unit, making it a go-to for compact builds. The fully modular cables are a hit for keeping things tidy, but some folks ran into trouble with the cable lengths in bigger cases. While it's quiet at idle thanks to Zero RPM mode, the fan can definitely make itself heard when your system is really working hard. There's also some confusion about the ATX 3.0/3.1 labeling on the box, even though Corsair says it's 3.1 certified.
“Man, this thing is tiny but packs a punch for my mini-ITX build, but seriously, those cables are short, had to get extensions just to make it look halfway decent. My 4080 Super is happy though, so I guess it's worth it.”
Common Praise
- The compact SFX form factor fits perfectly in small cases, freeing up space.
- Fully modular Type-5 Micro-Fit connectors allow for clean cable routing and only connecting necessary cables.
- The Zero RPM fan mode keeps the unit silent during low to medium power draw.
- ATX 3.1 compliance and PCIe 5.1 readiness provide future-proofing for new GPUs.
- The included SFX-to-ATX bracket makes it adaptable for use in larger cases.
Common Complaints
- The included cables are reported as too short for effective cable management in some larger PC cases.
- The fan can become noticeably loud when the power supply is under heavy load.
- The price is a frequent point of discussion, being on the higher end for an 850W unit.
- Some users experienced issues with the included 12VHPWR cable causing GPU instability.
- There's confusion regarding the ATX 3.0 labeling on some boxes versus the advertised ATX 3.1 compliance.
Ownership Tips
- The fan curve can be aggressive, with the fan kicking in and becoming audible at higher loads, even if the Zero RPM mode works at lower loads.
- Initial use might involve a faint electrical smell, which typically dissipates after a break-in period.
- Despite the '2024' designation and ATX 3.1 claims, some units might arrive in packaging that still references ATX 3.0.
- The Type-5 Micro-Fit connectors, while compact, can be a minor inconvenience if you're looking for third-party custom sleeved cables.
Frequently Asked Questions
Is this power supply truly ATX 3.1 compliant, even if the box says ATX 3.0?
Yes, Corsair has stated that their ATX 3.0 PSUs are rated and certified for ATX 3.1, so even if the packaging shows 3.0, the unit meets the 3.1 standard.
Are the cables compatible with older Corsair power supplies?
Corsair generally offers cross-PSU cable compatibility for most of their models, but it's recommended to check Corsair's website for a specific compatibility sheet for your older PSU.
How quiet is the fan operation?
The 92mm PWM fan features Zero RPM Mode, meaning it remains off at low to medium loads for silent operation. At full load, the fan can spin up to 2800 RPM, which can be audible.
What is the warranty period for this power supply?
The Corsair SF850 comes with a 7-year warranty, providing extended coverage for the unit.
Does it include a 12VHPWR cable for new GPUs?
Yes, a PCIe 5.1 12V-2x6 GPU cable is included, designed for use with modern graphics cards like the NVIDIA GeForce RTX 40 Series.
Buying Guide
When you're picking a power supply, you're essentially choosing the heart of your PC. It needs to deliver enough power for all your components, especially your CPU and GPU, without wasting energy or making too much noise. For small computers, the physical size of the power supply is just as important as its power output.
Wattage
Form Factor (SFX)
80 PLUS Platinum
ATX 3.1 / PCIe 5.1 Ready
Alternatives
If you need more than 850 watts or have a larger case with more room, look for SFX-L or standard ATX power supplies with higher wattage ratings like 1000W or 1200W.
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