Buying Guide
The Best Quiet Power Supplies
We weighed five power supplies on rated output and native 12V-2x6 cable count; the Thermaltake Toughpower GT 850W has the highest rated output, and the Thermaltake Smart BM3 650W costs the least.
By The PC Journal editorial team
12 min read5 products evaluated
A power supply is quietest when its fan can stop at idle and light gaming loads. Every pick has a fan-stop mode, ordered from the lowest price.
Rankings weigh wattage, native 12V-2x6 cables and warranty as the makers state them; we did not test these power supplies ourselves, and if a maker skips native 12V-2x6 cables, the guide says so.
Quick Picks
Our 5 recommendations at a glance. Tap a pick for the full verdict.
Lowest Price Here
Thermaltake Smart BM3 650W
A lower price than the SAMA GT650 White and the rest when we checked.
Best for: Spending as little as possible.
Our take Check price for Thermaltake Smart BM3 650W (opens in a new tab)
Also Consider
SAMA GT650 White
An ECO silent mode for low-load quiet.
Best for: Buyers who want ECO silent mode for low-load quiet.
Our take Check price for SAMA GT650 White (opens in a new tab)
Strong Alternative
SAMA GT750
Japanese capacitors with an LLC and DC-DC design.
Best for: Buyers who want Japanese capacitors with an LLC and DC-DC design.
Longest Warranty
MONTECH Century II 550W
The longest warranty here (10 years).
Best for: Buyers who put warranty first.
Our take Check price for MONTECH Century II 550W (opens in a new tab)
Highest Rated Output
Thermaltake Toughpower GT 850W
The highest rated output here (850W).
Best for: Buyers who put rated output first.
Our take Check price for Thermaltake Toughpower GT 850W (opens in a new tab)
| Pick | Why it’s here | Best for | Price |
|---|---|---|---|
| A lower price than the SAMA GT650 White and the rest when we checked. | Spending as little as possible. | Check price for Thermaltake Smart BM3 650W (opens in a new tab) |
| An ECO silent mode for low-load quiet. | Buyers who want ECO silent mode for low-load quiet. | Check price for SAMA GT650 White (opens in a new tab) |
| Japanese capacitors with an LLC and DC-DC design. | Buyers who want Japanese capacitors with an LLC and DC-DC design. | Check price for SAMA GT750 (opens in a new tab) |
| The longest warranty here (10 years). | Buyers who put warranty first. | Check price for MONTECH Century II 550W (opens in a new tab) |
| The highest rated output here (850W). | Buyers who put rated output first. | Check price for Thermaltake Toughpower GT 850W (opens in a new tab) |
Our Picks
Lowest Price Here1 of 5
Thermaltake Smart BM3 650W on Amazon (opens in a new tab)
The Thermaltake Smart BM3 650W stands out for Japanese 105°C main capacitor, and it adds semi-modular cables: fixed main cables, detachable extras.
Best for
- Spending as little as possible.
Skip if
- Choose another pick if you can't accept this: a shorter 5-year warranty.
Why we like it
It also offers a 650W rated output and offers a 5 years warranty. It is 80 Plus Bronze and ATX 3.1 compliant for PCIe Gen 5 cards, with industrial-grade protections built in. It matches the SAMA GT650 White on rated output (650W).
On warranty it ties with the Thermaltake Toughpower GT 850W at 5 years. It is the only pick here with a bronze 80 plus rating; the MONTECH Century II 550W has a gold 80 plus rating instead. Semi-modular cabling is unique to it among these picks, while the SAMA GT750 uses fully modular cabling.
No other pick here cost less at our last price check, and the SAMA GT650 White was closest. If you want a confirmed native 12V-2x6 cable count, look to the SAMA GT650 White instead: it offers 1, while this one gives no figure.
Key dimensions & specs
- Wattage: 650W
- Warranty: 5 years
- 80 Plus rating: Bronze
- ATX version: ATX 3.1
- Form factor: ATX
- Cabling: Semi-modular
- Fan: 120mm
- Fan stop: Yes
- Colour: Black
Pros
- A 650W rating
- ATX 3.1 compliance
- A fan that stops at low load
- Japanese 105°C main capacitor
Cons
- A shorter 5-year warranty
- Only 80 Plus Bronze efficiency
- No published native 12V-2x6 cable count
Also Consider2 of 5
SAMA GT650 White on Amazon (opens in a new tab)
SAMA's GT650 White is a fully modular white unit with embossed white cables, a native 12V-2x6 cable and an ECO silent mode.
Best for
- Buyers who want ECO silent mode for low-load quiet.
Skip if
- Its warranty is not published, which rules it out if you need that number.
Why we like it
Japanese capacitors support long-term durability, and a native 12V-2x6 connector feeds current graphics cards. It is 80 Plus Gold rated. On rated output it ties with the Thermaltake Smart BM3 650W at 650W.
You get a white colour here, which sets it apart from the Thermaltake Toughpower GT 850W and its a black colour. The SAMA GT650 White comes with a native 12V-2x6 cable, so a 16-pin card plugs in without an adapter. No depth is rated for the SAMA GT650 White, so check the maker's page against your case's PSU bay.
On price it sat second of 5, between the cheaper Thermaltake Smart BM3 650W and the pricier SAMA GT750, at the time of writing. The maker doesn't give its warranty; if that figure matters, the MONTECH Century II 550W offers 10 years.
Key dimensions & specs
- Wattage: 650W
- Native 12V-2x6 cables: 1
- ATX version: ATX 3.1
- Form factor: ATX
- Cabling: Fully modular
- Fan: 120mm
- Fan stop: Yes
- Colour: White
Pros
- A 650W rating
- A native 12V-2x6 cable for 16-pin cards
- ATX 3.1 compliance
- Fully modular cables
Cons
- No published warranty
- Costs more than the Thermaltake Smart BM3 650W at the time of writing
Strong Alternative3 of 5
SAMA GT750 on Amazon (opens in a new tab)
SAMA's GT750 uses Japanese capacitors with an LLC and DC-DC design, a native 12V-2x6 cable and an ECO silent mode for low loads.
Best for
- Buyers who want Japanese capacitors with an LLC and DC-DC design.
Skip if
- Skip it if you need to know its warranty before buying; the maker doesn't publish one.
Why we like it
Its ECO silent mode keeps the 120mm FDB fan quiet at low load, and Japanese capacitors with LLC and DC-DC topology support long-term stability. Embossed modular cables are easier to route. Its embossed modular cables improve airflow and make routing simpler.
Its 750W rated output ranks second of 5 here, behind the Thermaltake Toughpower GT 850W (850W) and ahead of the MONTECH Century II 550W (550W). The SAMA GT750 comes with a native 12V-2x6 cable, so a 16-pin card plugs in without an adapter. No depth is rated for the SAMA GT750, so check the maker's page against your case's PSU bay.
When we checked, only the SAMA GT650 White and cheaper picks cost less, and the MONTECH Century II 550W cost more. If you want a confirmed warranty, look to the MONTECH Century II 550W instead: it offers 10 years, while this one gives no figure.
Key dimensions & specs
- Wattage: 750W
- Native 12V-2x6 cables: 1
- Cybenetics rating: Gold
- ATX version: ATX 3.1
- Form factor: ATX
- Cabling: Fully modular
- Fan: 120mm
- Fan stop: Yes
- Colour: Black
Pros
- A 750W rating
- A native 12V-2x6 cable for 16-pin cards
- ATX 3.1 compliance
- Fully modular cables
Cons
- No published warranty
- Costs more than the Thermaltake Smart BM3 650W at the time of writing
Longest Warranty4 of 5
MONTECH Century II 550W on Amazon (opens in a new tab)
Montech's Century II 550W is a fully modular 80 Plus Gold unit with a native 12V-2x6 cable and a 10-year warranty, unusual at this wattage.
Best for
- Buyers who put warranty first.
Skip if
- Skip it if rated output matters most to you; the Thermaltake Toughpower GT 850W offers 850W.
Why we like it
Its 135mm FDB fan has a zero RPM mode, and it uses 100% Japanese capacitors. The silver metallic finish is MONTECH's signature look. It is ATX 3.1 and PCIe 5.1 ready with a 12V-2x6 cable.
On rated output it trails the group at 550W, while the Thermaltake Toughpower GT 850W offers 850W. Its 10 years warranty is the longest here; the Thermaltake Smart BM3 650W comes next at 5 years. It shares a gold 80 plus rating with the Thermaltake Toughpower GT 850W; the Thermaltake Smart BM3 650W goes with a bronze 80 plus rating.
It also offers a 135mm fan that can stop at low load. The MONTECH Century II 550W comes with a native 12V-2x6 cable, so a 16-pin card plugs in without an adapter. Its price falls between the SAMA GT750 and the Thermaltake Toughpower GT 850W, based on our last check.
Key dimensions & specs
- Wattage: 550W
- Native 12V-2x6 cables: 1
- Warranty: 10 years
- 80 Plus rating: Gold
- ATX version: ATX 3.1
- Form factor: ATX
- Cabling: Fully modular
- Fan: 135mm
- Fan stop: Yes
- Colour: Black
Pros
- A 550W rating
- A native 12V-2x6 cable for 16-pin cards
- A 10-year warranty
- ATX 3.1 compliance
Cons
- Rated output trails the Thermaltake Toughpower GT 850W (850W)
- Costs more than the Thermaltake Smart BM3 650W at the time of writing
Highest Rated Output5 of 5
Thermaltake Toughpower GT 850W on Amazon (opens in a new tab)
Thermaltake's Toughpower GT 850W is a fully modular ATX 3.1 unit with a native 12V-2x6 cable, a single high-amperage 12V rail and a Smart Zero Fan mode.
Best for
- Buyers who put rated output first.
Skip if
- Pass on it if a shorter 5-year warrant rules it out for your setup.
Why we like it
Smart Zero Fan keeps the fan off at low load, and its low-profile flat black cables are easy to route. It is 80 Plus Gold rated at up to 90% efficiency. On rated output it leads this guide at 850W, ahead of the SAMA GT750 (750W).
On warranty it ties with the Thermaltake Smart BM3 650W at 5 years. Like the MONTECH Century II 550W, it has a gold 80 plus rating, while the Thermaltake Smart BM3 650W uses a bronze 80 plus rating. The Thermaltake Toughpower GT 850W comes with a native 12V-2x6 cable, so a 16-pin card plugs in without an adapter.
At our last price check it topped the group, with the MONTECH Century II 550W the nearest cheaper option. Native 12V-2x6 cable count is its weakest area, and the SAMA GT650 White covers it better at 1.
Key dimensions & specs
- Wattage: 850W
- Native 12V-2x6 cables: 1
- Warranty: 5 years
- 80 Plus rating: Gold
- ATX version: ATX 3.1
- Form factor: ATX
- Cabling: Fully modular
- Fan stop: Yes
- Colour: Black
Pros
- A 850W rating
- A native 12V-2x6 cable for 16-pin cards
- ATX 3.1 compliance
- Fully modular cables
Cons
- A shorter 5-year warranty
- Warranty trails the MONTECH Century II 550W (10 years)
- Costs more than the Thermaltake Smart BM3 650W at the time of writing
How We Chose These Quiet Power Supplies
Each pick was assessed across 4 criteria weighted for real-world use.
- Standards
- We noted ATX version, 80 Plus and Cybenetics ratings.
- Price
- We grouped picks by price at the time of writing.
- Connectors
- We recorded native 12V-2x6 cables and PCIe 8-pin connectors where the listing states them.
- Build and warranty
- We checked depth, modular cabling, fan-stop modes and warranty length.
What to Look for in Quiet Power Supplies
Key buying criteria so you get the right fit the first time.
Where these picks differ: rated output
Among these picks, rated output runs from 550W on the MONTECH Century II 550W to 850W on the Thermaltake Toughpower GT 850W. Match this to what you will actually do with it, then let price decide between the picks that qualify.
Match the power connector
Most RTX 40 and RTX 50 cards use a single 16-pin 12V-2x6 (12VHPWR) plug, while many Radeon cards use two or three 8-pin plugs. A native cable avoids bulky adapters.
Push the 16-pin plug fully home and avoid a sharp bend right at the connector.
Compare efficiency ratings
80 Plus and Cybenetics ratings describe how much power turns into heat. Gold is the usual target for a gaming PC; Platinum and Titanium run cooler and cost more.
Check depth and cabling
Deeper units can clash with drive cages or front radiators. Fully modular cables make routing easier in tight cases.
Use the warranty as a quality signal
Long warranties of seven to twelve years show how long a maker expects a unit to last. A power supply often moves from one build to the next, so the warranty matters.
How to Choose Quiet Power Supplies
By priority
| Priority | Consider | Why |
|---|---|---|
| Spending as little as possible | Thermaltake Smart BM3 650W | A lower price than the SAMA GT650 White and the rest when we checked |
| Buyers who want ECO silent mode for low-load quiet | SAMA GT650 White | An ECO silent mode for low-load quiet |
| Buyers who want Japanese capacitors with an LLC and DC-DC design | SAMA GT750 | Japanese capacitors with an LLC and DC-DC design |
| Buyers who put warranty first | MONTECH Century II 550W | The longest warranty here (10 years) |
| Buyers who put rated output first | Thermaltake Toughpower GT 850W | The highest rated output here (850W) |
Scroll sideways to see every column.
Key specs side by side
Figures as each maker states them.
| Power supplie | Wattage | Native 12V-2x6 cables | Warranty | 80 Plus rating |
|---|---|---|---|---|
| Thermaltake Smart BM3 650W | 650W | Not listed | 5 years | Bronze |
| SAMA GT650 White | 650W | 1 | Not listed | Not listed |
| SAMA GT750 | 750W | 1 | Not listed | Not listed |
| MONTECH Century II 550W | 550W | 1 | 10 years | Gold |
| Thermaltake Toughpower GT 850W | 850W | 1 | 5 years | Gold |
Scroll sideways to see every column.
Frequently Asked Questions
Which pick leads on warranty?
The MONTECH Century II 550W, at 10 years. The Thermaltake Smart BM3 650W follows at 5 years, while the Thermaltake Toughpower GT 850W has 5 years.
Which pick costs the least here?
Start with the Thermaltake Smart BM3 650W, the lowest-priced pick when we checked. The Thermaltake Toughpower GT 850W is the premium end, so the spread between them shows what extra money buys here.
Is an ATX 3.0 power supply still fine?
Generally yes. ATX 3.1 mainly revises the connector to 12V-2x6 and relaxes some spike requirements; check your unit's cable is rated for your card.
Does a Platinum unit save much on electricity?
Only a little for most gaming PCs. The main gains are less heat and often a quieter fan.
Can I reuse the power supply from my old PC?
Only if it meets the card's wattage and connector needs and is still under warranty or in good health. Very old units lack modern connectors.
Bottom Line
Our first pick is the Thermaltake Smart BM3 650W, chosen for a lower price than the SAMA GT650 White and the rest when we checked. Look at the SAMA GT650 White for an ECO silent mode for low-load quiet, the SAMA GT750 for Japanese capacitors with an LLC and DC-DC design and the MONTECH Century II 550W for the longest warranty here (10 years) if those matter more to you.
Mount the PSU fan-down over a filtered intake if the case allows it.