SilverStone 700W SFX 80 Plus vs SilverStone 500W Flex ATX Power: Spec Comparison
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You are comparing the silverstone technology sst sx700 g 700w sfx vs technology fx500 g to find the right power supply for your build. Both units share 80 PLUS Gold efficiency and Japanese capacitors for reliable performance. The main difference lies in their physical design and power capacity. One offers higher wattage in a standard SFX frame, while the other provides a slimmer Flex ATX profile for compact cases. You need to check your case dimensions and power needs to decide.
Key differences
| Aspect | SilverStone 700W SFX 80 Plus Gold Power Supply | SilverStone 500W Flex ATX Power Supply |
|---|---|---|
| Wattage | 700W | 500W |
| Form Factor | SFX | Flex ATX |
| Modularity | Fully Modular | not listed |
| Fan Size | 92mm | not listed |
| Dimensions | 4.92 x 3.94 x 2.5 inches | 5.91 x 3.21 x 1.59 inches |
Which one should you choose?
Choose SilverStone 700W SFX 80 Plus Gold Power Supply if
- You need 700W of continuous power for high-end components
- Your case supports the standard SFX mounting holes
- You prefer fully modular cables for cleaner cable management
Choose SilverStone 500W Flex ATX Power Supply if
- You are building in a very low-profile or specialized chassis
- You require the slimmer 1.59-inch height of the Flex ATX form factor
- Your system power draw stays well below 500W
Verdict: Choose the 700W SFX unit if you need maximum power and standard SFX compatibility. Select the 500W Flex ATX model if your case requires the ultra-slim profile. Both deliver efficient power, so your choice depends on physical constraints and wattage requirements.
Specs: SFX Gold vs Flex ATX
Form factor
The SilverStone 700W SFX 80 Plus Gold uses the standard SFX form factor. Its dimensions are 3.94 inches wide, 2.5 inches high, and 4.92 inches long. This unit is not compatible with ATX power supply mounting holes. The SilverStone 500W Flex ATX Power Supply supports the Flex ATX standard. It measures 3.21 inches wide, 1.59 inches high, and 5.91 inches long. You must match the power supply to your case mounting points. The SFX unit is taller but shorter in length. The Flex ATX unit is lower and longer. Choose based on your chassis specifications.
Power output
Power output is a key difference between these two units. The SilverStone 700W SFX 80 Plus Gold provides 700W of continuous power. The SilverStone 500W Flex ATX Power Supply provides 500W of continuous power. The Flex ATX model is rated for 24/7 operation at 40℃ operating temperature. If your build requires more power, the SFX model offers 200W more headroom. The Flex ATX model is suitable for lower power systems. Consider your CPU and GPU power requirements before deciding. Higher wattage allows for more future upgrades.
Modularity
Cable management affects airflow and build quality inside your case. The SilverStone 700W SFX 80 Plus Gold is fully modular. It includes 100% modular cables with flexible flat arrays. This allows you to connect only the cables you need. The SilverStone 500W Flex ATX Power Supply does not list modularity in its specifications. You must assume it has fixed cables if not specified. Fully modular designs reduce clutter. They make installing the power supply easier in tight spaces. This is a significant advantage for the SFX model.
Fan size
The cooling fan size impacts noise and airflow. The SilverStone 700W SFX 80 Plus Gold uses a 92mm fan. It features an FDB fan with a minimum noise level of 18 dBA. The SilverStone 500W Flex ATX Power Supply does not list fan specifications in the provided data. A larger fan can move more air at lower speeds. This often results in quieter operation. The 92mm fan on the SFX model is larger than typical fans in smaller units. Check if the Flex ATX unit has a smaller fan that may run louder.
Weight
Weight can matter for small form factor builds. The SilverStone 700W SFX 80 Plus Gold weighs 3.09 pounds. The SilverStone 500W Flex ATX Power Supply weighs 2.87 pounds. The Flex ATX unit is slightly lighter by 0.22 pounds. This difference is minimal for most installations. Both units are relatively lightweight compared to larger ATX power supplies. The weight difference is unlikely to affect your build stability. Focus on the form factor and power needs instead of this small variance.
Which Silverstone PSU fits your build
Users needing high power in standard SFX cases
You should choose the 700W SFX unit if your case supports the standard SFX form factor. It delivers 700W of continuous power, which is significantly higher than the 500W alternative. The 92mm fan ensures quiet operation at 18 dBA, and the fully modular cables help with cable management in standard mid-tower or small form factor builds.
Owners of compact Flex ATX chassis
If your case uses the Flex ATX mounting standard, this 500W unit is the correct choice. Its compact height of 1.59 inches fits into smaller enclosures where the taller SFX unit would not fit. It provides 500W of power at 40 degrees Celsius, making it suitable for 24/7 operation in tight spaces.
Builders prioritizing modular cabling and quiet fans
This 700W model offers fully modular cables with flexible flat arrays, which simplifies routing in tight spaces. It also features a 92mm fluid dynamic bearing fan for silent running. If you value quiet operation and clean cable management alongside higher wattage, this SFX unit provides better connectivity and acoustic performance for your system.
The products compared
SilverStone 700W SFX 80 Plus Gold Power Supply
Best for: high-power small form factor builds
- Wattage
- 700W
- Efficiency Rating
- 80 PLUS Gold
- Modularity
- Fully Modular
- Fan Size
- 92mm
- Form Factor
- SFX
- Dimensions
- 4.92 × 3.94 × 2.5 inches
View on Amazon: SilverStone 700W SFX 80 Plus Gold Power Supply Affiliate link
This SilverStone unit delivers 700W of power in a compact SFX form factor. It features 80 PLUS Gold efficiency and fully modular flat cables. The 92mm fan ensures quiet operation at 18 dBA. It suits users needing high wattage in small cases. The single +12V rail offers strict voltage regulation. This model fits standard SFX mounting holes.
Pros
- 700W output capacity
- 80 PLUS Gold efficiency
- Fully modular flat cables
- 18 dBA quiet fan operation
Cons
- SFX form factor limits case compatibility
- Heavier at 3.09 pounds
- Not compatible with ATX mounting holes
Good fit if
- You need high wattage in a small case
- You prefer fully modular cable management
- You require strict voltage regulation
Skip if
- You require an ATX form factor
- You need a larger 120mm fan
- You want a non-modular design
Verdict: SilverStone 700W SFX Gold PSU provides robust power for compact builds. It fits users who need 700W in an SFX case with quiet operation.
SilverStone 500W Flex ATX Power Supply
Best for: small form factor builds
- Wattage
- 500W
- Efficiency Rating
- 80 PLUS Gold
- Form Factor
- Flex ATX
- Dimensions
- 5.91 × 3.21 × 1.59 inches
- Weight
- 2.87 pounds
View on Amazon: SilverStone 500W Flex ATX Power Supply Affiliate link
This 500W Flex ATX power supply delivers 80 PLUS Gold efficiency. It features a 500W continuous output rated for 24/7 operation at 40°C. The unit uses a Japanese primary capacitor and a single +12V rail. Its compact dimensions allow it to fit in small form factor builds. You get reliable performance in a dense package.
Pros
- 500W continuous output
- 80 PLUS Gold efficiency
- Japanese primary capacitor
- Compact 3.21 x 1.59 x 5.91 inch size
Cons
- Lower wattage than the 700W SFX option
- Heavier at 2.87 pounds
- Single +12V rail limits flexibility
Good fit if
- You need a compact Flex ATX PSU
- You require 80 PLUS Gold efficiency
- You build a small form factor PC
Skip if
- You need more than 500W
- You prefer an SFX form factor
- You want a modular design
Verdict: Silverstone FX500-G 500W Flex ATX fits small cases where space is tight but efficiency matters. It suits users who prioritize compact dimensions over higher wattage.
Specifications side by side
| Spec | SilverStone 700W SFX 80 Plus Gold Power Supply | SilverStone 500W Flex ATX Power Supply |
|---|---|---|
| Wattage | 700W | 500W |
| Efficiency Rating | 80 PLUS Gold | 80 PLUS Gold |
| Modularity | Fully Modular | not stated |
| Fan Size | 92mm | not stated |
| Form Factor | SFX | Flex ATX |
| Size | 700W | 500W |
| Dimensions | 4.92 × 3.94 × 2.5 inches | 5.91 × 3.21 × 1.59 inches |
| Weight | 3.09 pounds | 2.87 pounds |
| Color | Black?Lead-Free Paint? | not stated |
| Model | SST-SX700-G | not stated |
Frequently asked questions
Does the SilverStone 700W SFX fit in a Flex ATX case?
No, the SilverStone 700W SFX unit uses the standard SFX form factor. Its dimensions are 3.94 inches wide, 2.5 inches high, and 4.92 inches long. This size is not compatible with Flex ATX mounting holes. You must use a case designed for standard SFX power supplies to install this unit.
Which power supply is smaller in height?
The SilverStone 500W Flex ATX is thinner. It measures 1.59 inches in height. The SilverStone 700W SFX unit is 2.5 inches high. If your case has strict height limitations, the Flex ATX model provides more vertical clearance. This makes it suitable for very tight builds.
Are both units fully modular?
The SilverStone 700W SFX is fully modular. This lets you connect only the cables you need. The provided data does not list the modularity type for the SilverStone 500W Flex ATX. You should check the product page for the Flex ATX model to confirm its cable configuration before buying.
Which unit weighs less?
The SilverStone 500W Flex ATX is lighter. It weighs 2.87 pounds. The SilverStone 700W SFX unit weighs 3.09 pounds. The difference is small, but the Flex ATX model is slightly more compact in mass. This may matter if you are building a portable system.
Can I use the 700W SFX in an ATX case?
No, the SilverStone 700W SFX is not compatible with ATX power supply mounting holes. It is designed specifically for SFX cases. You need a case that supports the standard SFX form factor. Using it in an ATX case without an adapter may cause fitting issues.
What is the length difference between the two units?
The SilverStone 500W Flex ATX is longer. It measures 5.91 inches in length. The SilverStone 700W SFX unit is 4.92 inches long. The Flex ATX model extends further. Ensure your case has enough depth to accommodate the longer Flex ATX unit if you choose that option.