PC Power Supply Selection: The Ultra-Comprehensive 2025 Guide

Power supply is literally the heart of your machine. It is what transforms the current from your wall socket into energy usable by your processor, your graphics card, your disks, your fans... In short, everything that lives in your case.

💥 And if it fails? It could be a disaster:

• Random instabilities at play
• Random restarts
• Grilled components
• ...or worse: a fire in your case (yes, it happens)

👉 Just so you know choose the right PC power supply , it's life insurance for your setup.

To answer the question that everyone is asking - how to choose your PC power supply ? we will detail the 5 aspects to consider.

It's THE number 1 question: how many watts for my PC? The answer depends 90% on your graphics card and your processor .

💡 How to determine the power needed for your PC power supply?

Here is a simple and reliable method:

• Add the TDP of your CPU + GPU
• Add 30% margin for consumption peaks
• Don't forget about small consumers (fans, SSDs, RGB...)
• Rounded up to the next level (550 W, 650 W, 750 W, 850 W...)

🔧 Concrete example:

• Ryzen 7 7800X3D → ~150 W under load
• RTX 4070 Ti → ~285 W under load
• Total = 435 W
• +30% margin = ~565 W

👉 A PSU 650 W is perfect here.

This is what is called the PC power supply recommended power .

Do you want to go faster? You can calculate it directly from the site. MSI

When you see "Gold", "Bronze", or "Platinum" on a power supply, it's not just for show. It's a 80 PLUS certification which guarantees its effectiveness.

🟡 At DropReference, we recommend min. of Gold , unless you really have a super tight budget, in which case you can go for Bronze, but it's not ideal.

• ATX: standard size, the most common (tag "Standard size" on our website)
• SFX / SFX-L: compact format for small ITX cases (⚠️ watch out for heat!
• Flex / TFX: for very small formats or industrial PCs (rare in gaming)

🔎 Note: some SFX power supplies may cost more than an ATX of the same power!

There are three schools:

• Non modular : all cables are soldered, even those you don't need → clutter, reduced airflow
• Semi-modular : ATX cable + soldered CPU, the rest detachable
• Fully modular : you only connect what you need → great for looks and ventilation

➡️ At DropReference, modular is always recommended (tag "Cable management") because it's so much more convenient!

This is a CRUCIAL point, as two 750W Gold PSUs do not have the same reliability at all depending on their brand.

On DropReference, we tag brands in Top brand , Good brand or Attention brand so that you know right away if you can go there with your eyes closed.

Every modern GPU has a minimum power recommendation Nvidia and AMD indicate it on their website.

➕ We always recommend a power supply with a minimum margin of 30%. Never run at 100% load!

With DropReference you can have at a glance all the power supplies available in your country with our reviews directly on them using our tags. We let you check all that out below:

The price differences come from several factors:

• Quality of capacitors (Japanese or cheap?)
• Ventilation (noisy or silent?)
• Actual performance
• Warranty (3 years? 10 years?)
• Compatibility ATX 3.1 / PCIe 5.0

➡️ In 2025, PSUs ATX 3.1 beginning to democratize. They are compatible with the new GPU connectors (12V-2x6), more stable and more convenient.

How to know your current PC power supply?

Open your case, read the label on the power supply unit. Otherwise, check the invoice or the model in the BIOS (if integrated).

What is the best PC power supply?

It depends on your budget. But in 2025, the Corsair RMx Shift, Seasonic Prime, and Be Quiet! Pure Power clearly dominate the market.

What power supply for an RTX 4080 Super?

We recommend a 850 W Gold modular from a good brand.

Do we really need modular?

If you want a clean, well-ventilated, and easy-to-assemble PC → YES.

If we have to summarize:

• Power adapted to your GPU + margin
• Certification Gold mini
• Modularity for comfort
• Reliable brand (Seasonic, Corsair, Be Quiet!)
• And above all... DO NOT NEGLECT THIS COMPONENT