Seasonic Core GX ATX 3
A compact, solid mid-range unit. Great for smaller cases, but it gets loud when you push it.
- Efficiency
- 80+ Gold
- Modular
- Full
- Standard
- ATX 3
- Form factor
- ATX
- Outputs
- 650 / 750 / 850W
The verdict
At 140mm deep, the Core GX is shorter than most 850W units, which makes cable management easier in smaller cases.
Tom's Hardware and KitGuru both found it well built with good electrical performance. Both also found the fan gets loud at high loads, and it has no semi-passive mode, so the fan never switches off.
It comes with a 7-year warranty where many rivals offer 10, and both reviews think it's a little expensive for a Gold unit.
Seasonic Core GX ATX 3 reviews
Both reviews call it well built with good electrical performance, and both like its compact 140mm depth. Both also found the fan gets loud at high loads, and both think it's a little pricey for a Gold unit.
Both labs agree
- Well built, with good electrical performance and load regulation. Tom's HardwareKitGuru
- Compact 140mm depth and fully modular. Tom's HardwareKitGuru
- The fan gets loud at high loads. Tom's HardwareKitGuru
- Slightly expensive for its class. Tom's HardwareKitGuru
Where they differ
- Warranty: Tom's Hardware lists the 7-year warranty as a plus, KitGuru as a minus next to rivals' 10 years. Tom's HardwareKitGuru
Also worth knowing
- No semi-passive fan mode, so the fan always spins, and the over-current trigger points are set high. Tom's Hardware
- Uses Taiwanese TEAPO capacitors rather than the Japanese ones Seasonic often uses. KitGuru
The Seasonic Core GX-850 ATX 3 is a well-built and reliable power supplyCore GX-850 ATX 3KitGuruDecember 2024
Another fine performing power supply from Seasonic targeting the mid range audience.Core GX 850 ATX 3, 8/10
Reviews tested the 850W model.
Pick your output
- 650WMid-range builds, up to an RTX 5070 class card.Check 650W price
- 750WMid-range builds, up to an RTX 5070 Ti class card.Check 750W price
- 850WHigh-end builds, up to an RTX 5080 class card.Check 850W price
Sizes assume a typical processor. Check your build in the wattage guide.
Other Tier A at 850W
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Specs
| Tier on my list | A · High-end builds |
|---|---|
| Wattages | 650W, 750W, 850W |
| Efficiency | 80 Plus Gold |
| Modular | Fully modular |
| Standard | ATX 3 |
| Size | ATX |
| Released | 2024 |
Seasonic Core GX ATX 3 questions
Will the Seasonic Core GX ATX 3 fit a small case?
It's 140mm deep, shorter than many 850W units, which both reviews highlight as a plus for smaller cases.
Is the Core GX ATX 3 quiet?
At low and medium loads, yes. Both reviews found the fan ramps up noticeably above about 700W, and KitGuru measured 37.3 dBA at the full 850W.
Does the Core GX ATX 3 have a zero-RPM fan mode?
No. Tom's Hardware notes there's no hybrid fan mode, so the fan always spins, slowly at light loads.
What warranty does the Core GX ATX 3 have?
Seven years. KitGuru counts that against it, as many rivals offer ten.
Which Seasonic Core GX ATX 3 wattage should I get?
It comes in 650W, 750W, 850W. Match it to your graphics card using the output guide above, or the calculator for your exact parts.
Can I reuse cables from my old power supply with the Core GX?
Use the cables that came in the box. Modular cables aren't standard between brands, or even between generations from one brand, and the wrong cable can damage your parts.