Buying Guide
The Best ATX 3.1 Gaming Power Supplies
Five power supplies ranked on rated output and native 12V-2x6 cable count, where the Thermaltake Toughpower GT 1000W has the highest rated output; the darkFlash DG750 is the cheapest route in.
By The PC Journal editorial team
12 min read5 products evaluated
ATX 3.1 units handle GPU power spikes and include a native 12V-2x6 cable. Every pick is ATX 3.x with a native 12V-2x6 connector, ordered from the lowest price.
Rankings weigh wattage, native 12V-2x6 cables and warranty as the makers state them; if a maker skips warranty, the guide says so rather than guess, since we have not benched them.
Quick Picks
Our 5 recommendations at a glance. Tap a pick for the full verdict.
Lowest Price Here
darkFlash DG750
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 darkFlash DG750 (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
MONTECH Century II 550W
A 10-year warranty, unusual at this wattage.
Best for: Buyers who want 10-year warranty, unusual at this wattage.
Our take Check price for MONTECH Century II 550W (opens in a new tab)
Worth a Look
ASRock Steel Legend SL-850GW White
A dual-color 12V-2x6 cable.
Best for: Buyers who want dual-color 12V-2x6 cable.
Our take Check price for ASRock Steel Legend SL-850GW White (opens in a new tab)
Highest Rated Output
Thermaltake Toughpower GT 1000W
The highest rated output here (1000W).
Best for: Buyers who put rated output first.
Our take Check price for Thermaltake Toughpower GT 1000W (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 darkFlash DG750 (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) |
| A 10-year warranty, unusual at this wattage. | Buyers who want 10-year warranty, unusual at this wattage. | Check price for MONTECH Century II 550W (opens in a new tab) |
| A dual-color 12V-2x6 cable. | Buyers who want dual-color 12V-2x6 cable. | Check price for ASRock Steel Legend SL-850GW White (opens in a new tab) |
| The highest rated output here (1000W). | Buyers who put rated output first. | Check price for Thermaltake Toughpower GT 1000W (opens in a new tab) |
Our Picks
Lowest Price Here1 of 5
darkFlash DG750 on Amazon (opens in a new tab)
darkFlash's DG750 is a 140mm-deep 80 Plus Gold unit with a native 12V-2x6 cable and a hydraulic-bearing fan.
Best for
- Spending as little as possible.
Skip if
- Worth skipping when a shorter 5-year warrant is a problem.
Why we like it
Its warranty is 5 years. It is fully modular with a quiet HDB fan, 80 Plus Gold rated, and backed by a 5-year limited warranty. Its fully modular cables reduce clutter for first-time builders.
Its 750W rated output ranks third of 5 here, behind the Thermaltake Toughpower GT 1000W (1000W) and ahead of the MONTECH Century II 550W (550W). On warranty it trails the group at 5 years, while the MONTECH Century II 550W offers 10 years. It matches the Thermaltake Toughpower GT 1000W on depth (140mm).
Like the MONTECH Century II 550W and Thermaltake Toughpower GT 1000W, it has a black colour, while the SAMA GT650 White uses a white colour. It also comes with a 140mm body that leaves room for cables. It cost the least of the 5 picks at the time of writing, with the SAMA GT650 White the next step up.
Key dimensions & specs
- Wattage: 750W
- Native 12V-2x6 cables: 1
- Warranty: 5 years
- Depth: 140mm
- 80 Plus rating: Gold
- ATX version: ATX 3.1
- Form factor: ATX
- Cabling: Fully modular
- Colour: Black
Pros
- A 750W rating
- A native 12V-2x6 cable for 16-pin cards
- A short 140mm body
- ATX 3.1 compliance
Cons
- A shorter 5-year warranty
- Warranty trails the MONTECH Century II 550W (10 years)
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
- The maker gives no warranty, so look elsewhere if that figure decides it for you.
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 sits mid-pack at 650W: the Thermaltake Toughpower GT 1000W offers 1000W, and the MONTECH Century II 550W comes in at 550W.
It shares a white colour with the ASRock Steel Legend SL-850GW White; the darkFlash DG750 goes with 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.
Its price falls between the darkFlash DG750 and the MONTECH Century II 550W, based on our last check. Buyers who need a confirmed warranty should compare it with the MONTECH Century II 550W, which 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
- No published depth
- Costs more than the darkFlash DG750 at the time of writing
Strong Alternative3 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 want 10-year warranty, unusual at this wattage.
Skip if
- Skip it if rated output matters most to you; the Thermaltake Toughpower GT 1000W offers 1000W.
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 1000W offers 1000W. It matches the ASRock Steel Legend SL-850GW White on warranty (10 years). It shares a black colour with the darkFlash DG750 and Thermaltake Toughpower GT 1000W; the ASRock Steel Legend SL-850GW White goes with a white colour.
It also comes with 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. On price it sat third of 5, between the cheaper SAMA GT650 White and the pricier ASRock Steel Legend SL-850GW White, at the time of writing.
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 1000W (1000W)
- No published depth
- Costs more than the darkFlash DG750 at the time of writing
Worth a Look4 of 5
ASRock Steel Legend SL-850GW White on Amazon (opens in a new tab)
ASRock's Steel Legend SL-850GW is a white 850W unit, 150mm deep, with a dual-color 12V-2x6 cable and a 10-year warranty.
Best for
- Buyers who want dual-color 12V-2x6 cable.
Skip if
- Skip it if depth matters most to you; the darkFlash DG750 offers 140mm.
Why we like it
Its compact 150mm-deep body helps in smaller cases, and iCOOL fan control adjusts speed to load. The white finish suits light builds. Its 850W rated output ranks second of 5 here, behind the Thermaltake Toughpower GT 1000W (1000W) and ahead of the MONTECH Century II 550W (550W).
On warranty it ties with the MONTECH Century II 550W at 10 years. Its 150mm depth is the deepest in this group; the darkFlash DG750 leads at 140mm. Like the SAMA GT650 White, it has a white colour, while the Thermaltake Toughpower GT 1000W uses a black colour.
The ASRock Steel Legend SL-850GW White comes with a native 12V-2x6 cable, so a 16-pin card plugs in without an adapter. It was priced above the MONTECH Century II 550W and below the Thermaltake Toughpower GT 1000W at the time of writing. It gives ground on depth, where the darkFlash DG750 comes in at 140mm.
Key dimensions & specs
- Wattage: 850W
- Native 12V-2x6 cables: 1
- Warranty: 10 years
- Depth: 150mm
- 80 Plus rating: Gold
- Cybenetics rating: Platinum
- ATX version: ATX 3.1
- Form factor: ATX
- Cabling: Fully modular
- Fan: 135mm
- Colour: White
Pros
- A 850W rating
- A native 12V-2x6 cable for 16-pin cards
- A 10-year warranty
- ATX 3.1 compliance
Cons
- Depth trails the darkFlash DG750 (140mm)
- Costs more than the darkFlash DG750 at the time of writing
Highest Rated Output5 of 5
Thermaltake Toughpower GT 1000W on Amazon (opens in a new tab)
Thermaltake's Toughpower GT 1000W is only 140mm deep, short for its wattage, and ships with a native 12V-2x6 cable and flat modular cables.
Best for
- Buyers who put rated output first.
Skip if
- Skip it if you need to know its warranty before buying; the maker doesn't publish one.
Why we like it
Its flat modular cables have colour-matched connectors, and a hydraulic-bearing fan with Smart Zero Fan keeps it quiet. Nothing else here matches its 1000W rated output; the ASRock Steel Legend SL-850GW White comes closest at 850W. It matches the darkFlash DG750 on depth (140mm).
Like the darkFlash DG750 and MONTECH Century II 550W, it has a black colour, while the SAMA GT650 White uses a white colour. The Thermaltake Toughpower GT 1000W comes with a native 12V-2x6 cable, so a 16-pin card plugs in without an adapter. At 140mm deep, compare it with your case's PSU clearance before buying.
At our last price check it topped the group, with the ASRock Steel Legend SL-850GW White the nearest cheaper option. Native 12V-2x6 cable count is its weakest area, and the darkFlash DG750 covers it better at 1.
Key dimensions & specs
- Wattage: 1000W
- Native 12V-2x6 cables: 1
- Depth: 140mm
- 80 Plus rating: Gold
- ATX version: ATX 3.1
- Form factor: ATX
- Cabling: Fully modular
- Fan: 120mm
- Fan stop: Yes
- Colour: Black
Pros
- 1000W of rated output for high-power cards
- A native 12V-2x6 cable for 16-pin cards
- A short 140mm body
- ATX 3.1 compliance
Cons
- No published warranty
- Costs more than the darkFlash DG750 at the time of writing
How We Chose These ATX 3.1 Gaming Power Supplies
Each pick was assessed across 4 criteria weighted for real-world use.
- How these picks were ranked
- We compared five power supplies on rated output, native 12V-2x6 cable count, warranty and depth from manufacturer specifications. We did not test them in-house.
- What every pick has in common
- All 5, from the darkFlash DG750 to the Thermaltake Toughpower GT 1000W, state rated output, native 12V-2x6 cable count and ATX version and share ATX 3.1 ATX version and Fully modular cabling.
- Where the specs have gaps
- The SAMA GT650 White and the Thermaltake Toughpower GT 1000W give no warranty; the SAMA GT650 White and the MONTECH Century II 550W give no depth.
- Price range
- From the darkFlash DG750 to the Thermaltake Toughpower GT 1000W, all sat in the $50 to $100 tier when we checked.
What to Look for in ATX 3.1 Gaming Power Supplies
Key buying criteria so you get the right fit the first time.
Rated output
Here rated output runs from 550W on the MONTECH Century II 550W to 1000W on the Thermaltake Toughpower GT 1000W. The ASRock Steel Legend SL-850GW White comes second for less money.
Warranty across these picks
Here warranty runs from 5 years on the darkFlash DG750 to 10 years on the MONTECH Century II 550W. The MONTECH Century II 550W is the pick for warranty. No figure for the SAMA GT650 White and the Thermaltake Toughpower GT 1000W.
Depth across these picks
Here depth runs from 150mm on the ASRock Steel Legend SL-850GW White to 140mm on the darkFlash DG750. Start with the darkFlash DG750 if depth decides it. No figure for the SAMA GT650 White and the MONTECH Century II 550W.
Setup checks
The darkFlash DG750 comes with a native 12V-2x6 cable, so a 16-pin card plugs in without an adapter.
Extras that separate them
The MONTECH Century II 550W: a 135mm fan that can stop at low load. The ASRock Steel Legend SL-850GW White: a 10-year warranty on a white unit. The Thermaltake Toughpower GT 1000W: flat cables for easier routing.
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.
How to Choose ATX 3.1 Gaming Power Supplies
By priority
| Priority | Consider | Why |
|---|---|---|
| Spending as little as possible | darkFlash DG750 | 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 10-year warranty, unusual at this wattage | MONTECH Century II 550W | A 10-year warranty, unusual at this wattage |
| Buyers who want dual-color 12V-2x6 cable | ASRock Steel Legend SL-850GW White | A dual-color 12V-2x6 cable |
| Buyers who put rated output first | Thermaltake Toughpower GT 1000W | The highest rated output here (1000W) |
Scroll sideways to see every column.
Key specs side by side
The Thermaltake Toughpower GT 1000W leads on rated output at 1000W, ahead of the ASRock Steel Legend SL-850GW White at 850W. "Not listed" means the maker leaves that figure out.
| Power supplie | Wattage | Native 12V-2x6 cables | Warranty | Depth |
|---|---|---|---|---|
| darkFlash DG750 | 750W | 1 | 5 years | 140mm |
| SAMA GT650 White | 650W | 1 | Not listed | Not listed |
| MONTECH Century II 550W | 550W | 1 | 10 years | Not listed |
| ASRock Steel Legend SL-850GW White | 850W | 1 | 10 years | 150mm |
| Thermaltake Toughpower GT 1000W | 1000W | 1 | Not listed | 140mm |
Scroll sideways to see every column.
Frequently Asked Questions
Which has the highest rated output: the Thermaltake Toughpower GT 1000W or the ASRock Steel Legend SL-850GW White?
The Thermaltake Toughpower GT 1000W leads at 1000W, with the ASRock Steel Legend SL-850GW White at 850W. The MONTECH Century II 550W is at the other end of this group with 550W.
What does the Thermaltake Toughpower GT 1000W add over the darkFlash DG750?
On paper it adds rated output (1000W against 750W). The darkFlash DG750 was the lowest-priced pick when we checked, so pay the difference only if those gains matter to you.
Why is the Thermaltake Toughpower GT 1000W our Highest Rated Output pick?
It earns the label for the highest rated output here (1000W). It suits anyone who put rated output first.
Does the SAMA GT650 White have fan stop, and which others do?
The SAMA GT650 White, the MONTECH Century II 550W and the Thermaltake Toughpower GT 1000W have it. The makers of the darkFlash DG750 and the ASRock Steel Legend SL-850GW White don't say.
Will the MONTECH Century II 550W work with my setup?
The MONTECH Century II 550W comes with a native 12V-2x6 cable, so a 16-pin card plugs in without an adapter. No depth is rated for the MONTECH Century II 550W, so check the maker's page against your case's PSU bay. In this guide it ranks third of 5.
What extras do the darkFlash DG750 and the SAMA GT650 White include?
The darkFlash DG750: a 140mm body that leaves room for cables. The SAMA GT650 White: an ECO silent mode for low-load quiet. The MONTECH Century II 550W: a 10-year warranty, unusual at this wattage.
Bottom Line
Our first pick is the darkFlash DG750, 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 MONTECH Century II 550W for a 10-year warranty, unusual at this wattage and the ASRock Steel Legend SL-850GW White for a dual-color 12V-2x6 cable if those matter more to you.
Seat the 12V-2x6 plug fully; a partly inserted plug can overheat.