TFX or Mini ITX PC Power Supplies? Compared by Specs
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You are comparing a TFX vs Mini ITX PC power supply to find the right fit for your build. Both units deliver stable power for compact systems, but they target different physical constraints and efficiency needs. The BackPlanePro offers a standard TFX footprint with a larger fan, while the FSP unit uses a slim Mini ITX form factor and achieves higher energy efficiency. Understanding these spec differences helps you match the unit to your case and performance goals.
Key differences
| Aspect | BackPlanePro 300W TFX Power Supply | FSP 400W Gold Flex ATX Mini ITX Power Supply |
|---|---|---|
| Form Factor | TFX | Mini ITX |
| Efficiency Rating | not listed | 80 Plus Gold |
| Wattage | 300W | 400W |
| Fan Size | 80mm | 4 cm |
| Dimensions (W x H x L) | 2.56 x 3.35 x 6.89 inches | 1.6 x 3.25 x 5.9 inches |
Which one should you choose?
Choose BackPlanePro 300W TFX Power Supply if
- You need a TFX form factor to fit a specific MicroATX slim case.
- You prefer a larger 80mm fan for potentially lower noise at idle.
- Your system requires a 300W unit and you prioritize compatibility with older Dell SFF replacements.
Choose FSP 400W Gold Flex ATX Mini ITX Power Supply if
- You require higher energy efficiency with an 80 Plus Gold certification.
- You need more power headroom with a 400W output rating.
- You are building in a very tight space where the slimmer Mini ITX dimensions are necessary.
Verdict: Choose the BackPlanePro if your case strictly requires the TFX form factor or if you are replacing an older Dell unit. Select the FSP model if you need higher efficiency, more wattage, or a smaller physical footprint for a Mini ITX build.
TFX vs Mini ITX PSU Specs
Efficiency Rating
The FSP unit carries an 80 Plus Gold certification, indicating it maintains an efficiency greater than 90% under typical loads. This means less energy is lost as heat during conversion. The BackPlanePro listing does not specify an 80 Plus rating. Without this data, you cannot confirm its energy savings. Higher efficiency reduces electricity costs and lowers internal temperatures. For users prioritizing power savings and cooler operation, the certified Gold rating provides a clear technical advantage over the unspecified efficiency of the TFX model.
Wattage Output
Power capacity differs between the two units. The FSP Mini ITX supply delivers 400W of total power. The BackPlanePro TFX unit provides 300W. If your system components require more than 300W, the TFX unit may struggle to support peak loads. The FSP unit offers a 33% higher power ceiling. This extra headroom allows you to run slightly more demanding components or ensures the supply operates at lower stress levels. For higher power needs, the FSP option is the stronger choice.
Physical Dimensions
Size constraints dictate which unit fits your case. The BackPlanePro TFX measures 6.89 inches in length, 3.35 inches in height, and 2.56 inches in width. It weighs 3 pounds. The FSP Mini ITX unit is shorter at 5.9 inches long, with a height of 3.25 inches and a width of 1.6 inches. It weighs 2 pounds. The FSP unit is slimmer and lighter. However, the TFX has a larger volume. You must check your case compatibility. The TFX fits standard TFX slots, while the FSP fits Mini ITX or Flex ATX spaces.
Cooling Fan
Thermal management relies on the internal fans. The BackPlanePro uses an 80mm silent fan to cool the unit. Larger fans generally move more air at lower speeds. The FSP unit uses a 4 cm fan, which is quite small. Small fans often spin faster to move the same amount of air, which can increase noise. The FSP marketing claims low noise, but the physical size difference is significant. An 80mm fan typically offers quieter operation than a 40mm fan at similar airflow levels. This favors the BackPlanePro for acoustic performance.
Warranty Coverage
Long-term reliability support varies. The BackPlanePro explicitly states a one-year warranty. This provides you with a defined period for manufacturer support if the unit fails. The FSP listing mentions an MTBF of 100K hours at 25 degrees Celsius, which indicates expected lifespan under specific conditions. However, it does not list a specific warranty duration in the provided data. A stated warranty term is easier to verify for consumer protection. Without a listed warranty for the FSP, the BackPlanePro offers clearer coverage terms.
Choose your ideal compact PSU
Small form factor builders needing GPU support
The FSP 400W Gold includes a PCIe 6+2 pin connector, allowing you to power discrete graphics cards in tight Mini ITX cases. Its 80 Plus Gold rating ensures high efficiency above 90%, reducing heat and energy waste. The compact 4 cm fan operates quietly while delivering stable power for demanding components.
Users replacing Dell Inspiron SFF units
The BackPlanePro 300W TFX is designed to replace specific Dell Inspiron systems. It features an 80mm silent fan for reliable cooling in MicroATX slim cases. The standard TFX form factor fits larger chassis than Mini ITX units, offering a straightforward swap for older business PCs without requiring custom cabling or adapters.
Efficiency-focused users seeking low heat output
With 80 Plus Gold certification, this unit maintains efficiency greater than 90%. This reduces wasted energy as heat, keeping your Mini ITX case cooler. The high-quality internal components and resettable power shutdown add safety. It is ideal for users who prioritize energy savings and thermal management in compact builds.
Quick picks
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | BackPlanePro 300W TFX Power Supply | Slim MicroATX cases and Dell Inspiron SFF replacements | Check price of BackPlanePro 300W TFX Power Supply on Amazon |
| 2 | FSP 400W Gold Flex ATX Mini ITX Power Supply | Mini ITX builds needing high efficiency | Check price of FSP 400W Gold Flex ATX Mini ITX Power Supply on Amazon |
The products compared
BackPlanePro 300W TFX Power Supply
Best for: Slim MicroATX cases and Dell Inspiron SFF replacements
- Form Factor
- TFX (what this guide is about)
- Wattage
- 300W
- Fan Size
- 80mm
- Warranty
- One Year
- Dimensions
- 6.89 × 2.56 × 3.35 inches
- Weight
- 3 pounds
View on Amazon: BackPlanePro 300W TFX Power Supply Affiliate link
This BackPlanePro unit is a 300W TFX power supply designed for slim MicroATX cases. It features an 80mm silent fan for cooling and active PFC for efficiency. The build measures 6.89 by 3.35 by 2.56 inches and weighs 3 pounds. It suits users needing a compact replacement for Dell Inspiron SFF systems. The one-year warranty covers basic reliability for small form factor builds.
Pros
- 300W output capacity for low-power systems
- 80mm silent fan for quiet operation
- Active PFC for efficient power conversion
- Compact TFX form factor fits slim cases
Cons
- Lower 300W wattage limits high-performance builds
- Short one-year warranty period
- 80mm fan size may be noisier than larger units
Good fit if
- You need a TFX PSU for a MicroATX slim case
- You are replacing a Dell Inspiron SFF power supply
- You prioritize silent operation with an 80mm fan
Skip if
- You require more than 300W of power
- You need a longer warranty than one year
- You are building a high-end gaming PC
Verdict: BackPlanePro 300W TFX Power Supply fits users building low-power systems in slim cases who need a direct replacement for Dell Inspiron SFF units.
FSP 400W Gold Flex ATX Mini ITX Power Supply
Best for: Mini ITX builds needing high efficiency
- Form Factor
- Mini ITX (what this guide is about)
- Wattage
- 400W
- Efficiency Rating
- 80 Plus Gold
- PCIe Connector Type
- 6+2 pin
- Fan Size
- 4 cm
- Dimensions
- 5.9 × 1.6 × 3.25 inches
View on Amazon: FSP 400W Gold Flex ATX Mini ITX Power Supply Affiliate link
This FSP Mini ITX power supply delivers 400W with 80 Plus Gold efficiency, meaning it wastes less energy as heat. The 4 cm fan keeps noise low while providing necessary airflow. It measures 5.9 by 3.25 by 1.6 inches, fitting tight Mini ITX cases. You get a PCIe 6+2 pin for graphics cards. It suits users needing high efficiency in a small form factor.
Pros
- 80 Plus Gold efficiency rating above 90%
- 400W output capacity
- Compact 5.9 inch length
- Includes PCIe 6+2 pin connector
Cons
- 4 cm fan may be less durable than larger units
- Heavier at 2 pounds for its size
- No mention of modular cabling
Good fit if
- You need high efficiency in a small case
- You build a Mini ITX system
- You require a PCIe 6+2 pin connector
Skip if
- You need a TFX form factor
- You want a fully modular cable setup
- You require a larger 120 mm fan
Verdict: FSP Mini ITX 400W Gold PSU fits Mini ITX builders who prioritize energy efficiency and compact dimensions over modular flexibility.
Specifications side by side
| Spec | BackPlanePro 300W TFX Power Supply | FSP 400W Gold Flex ATX Mini ITX Power Supply |
|---|---|---|
| Wattage | 300W | 400W |
| Efficiency Rating | not stated | 80 Plus Gold |
| PCIe Connector Type | not stated | 6+2 pin |
| Fan Size | 80mm | 4 cm |
| Warranty | One Year | not stated |
| Form Factor | TFX | Mini ITX |
| Dimensions | 6.89 × 2.56 × 3.35 inches | 5.9 × 1.6 × 3.25 inches |
| Weight | 3 pounds | 2 pounds |
| Color | Grey | not stated |
| Model | LYSB00CXAUQJK-CMPTRACCS | FSP400-60FGGBA |
| Size | not stated | 400W_Gold |
Frequently asked questions
Can I use a TFX power supply in a Mini ITX case?
You can, but only if the case supports TFX form factors. TFX units are generally taller and wider than Mini ITX PSUs. The BackPlanePro TFX measures 3.35 inches in height. Most Mini ITX cases are designed for the slimmer Mini ITX standard. Check your case manual before purchasing to ensure physical compatibility.
Which form factor is better for small GPU builds?
Mini ITX power supplies are often better for small GPU builds due to their compact width. The FSP Mini ITX unit is only 1.6 inches wide. This slim profile leaves more room for graphics cards and cables. TFX units are wider, which can restrict space in very tight chassis designs.
Do I need an 80 Plus Gold rating for a small PC?
An 80 Plus Gold rating is not strictly required, but it improves efficiency. The FSP Mini ITX unit carries this certification, meaning it loses less energy as heat. This keeps your small system cooler and quieter. The BackPlanePro TFX does not list an efficiency rating, so you may need to check the manual for details.
What is the weight difference between TFX and Mini ITX PSUs?
Mini ITX power supplies are typically lighter than TFX units. The FSP Mini ITX PSU weighs 2 pounds. The BackPlanePro TFX weighs 3 pounds. This weight difference matters when mounting the PSU in tight spaces or moving your small form factor PC frequently. The lighter unit may be easier to handle during installation.
Can a TFX PSU power a discrete graphics card?
It depends on the specific model and its connectors. The FSP Mini ITX PSU includes a PCIe 6+2 pin connector for discrete GPUs. The BackPlanePro TFX listing does not specify GPU connectors. You must verify the connector types on the TFX unit before using it with a graphics card that requires external power.
How do the dimensions affect cable management?
Dimensions dictate how much space you have for routing cables. The FSP Mini ITX unit is 5.9 inches long and 1.6 inches wide. The BackPlanePro TFX is 6.89 inches long and 3.35 inches wide. The narrower Mini ITX design often allows for tighter cable routing in small cases, reducing clutter and improving airflow.