6 Best Alternatives to the GAMEMAX GS Series SFX Power (2026)
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The GAMEMAX GS Series SFX Power Supply offers a compact, fully modular design with 80 Plus Gold efficiency. This makes it a practical choice for small form factor builds that require reliable power in a tight space. However, you might seek gamemax gs series sfx power alternatives if your needs differ from this specific configuration. Perhaps you need higher wattage for a more powerful GPU, or you are building in a standard ATX case rather than a small one. Some users also prefer different brand reputations or specific connector layouts that do not match this unit.
The alternatives listed here were chosen because their specifications overlap with the original product in key areas. You will find other SFX units that maintain high efficiency and modularity, such as the SilverStone and EVGA options. These provide similar compact benefits while offering different wattage levels or warranty terms. If your case allows, you can also look at ATX models like the Corsair RM series. These provide side-mounted connectors and modern ATX 3.1 support, which simplifies cable management for larger builds. Each option here addresses a specific gap in the original’s spec sheet.
Our top pick: GAMEMAX GS Series 650W SFX PSU.
How each alternative compares
GAMEMAX 850W SFX Gold Power Supply
The GAMEMAX 850W SFX Gold Power Supply keeps the compact SFX form factor and fully modular design of the original 650W model. It upgrades efficiency to 80 Plus Gold, matching your current choice, but delivers 200 more watts of power. This extra headroom suits high-density builds that need more juice without changing case sizes. You gain support for modern PCIe 5.0 standards, which the original does not specify. The trade-off is a higher power draw that may stress smaller cases. If you need more wattage in the same small footprint, this is the direct upgrade path.
Corsair RM850x Shift 850W White ATX Power Supply
The Corsair RM850x Shift 850W White ATX Power Supply switches from SFX to standard ATX size. This means it will not fit in small cases designed for the GAMEMAX GS Series. However, it offers ATX 3.1 and PCIe 5.1 support, providing modern connectivity for newer graphics cards. It retains full modularity and 80 Plus Gold efficiency, so you do not lose efficiency gains. The larger size allows for potentially better airflow and cable management in standard towers. Choose this if you are building in a mid-tower or full-tower case and need the latest PCIe standards rather than compact size.
Corsair RM750x Shift White 750W ATX Power Supply
The Corsair RM750x Shift 750W ATX Power Supply also moves to the standard ATX form factor, making it incompatible with SFX cases. It provides 750 watts, which is 100 watts more than the GAMEMAX GS Series. Like the RM850x, it features ATX 3.1 and PCIe 5.1 support, ensuring compatibility with the latest hardware. It is fully modular and 80 Plus Gold efficient, matching the original's efficiency class. The side-mounted connectors simplify cable management in standard cases. Select this option if you prioritize modern ATX standards and side connectors over the space-saving benefits of an SFX power supply.
Corsair RM1000e 1000W ATX Power Supply
The Corsair RM1000e 1000W ATX Power Supply is a significant step up in wattage, offering 1000 watts compared to the GAMEMAX GS Series 650W. It uses the standard ATX form factor, so it requires a larger case. It maintains full modularity and 80 Plus Gold efficiency, ensuring reliable power delivery. This unit is ideal for systems with high-power components that exceed the 650W limit. The larger size accommodates more robust internal components. If your build demands maximum power headroom and you have a standard ATX case, this provides substantial power without sacrificing efficiency or modularity.
SilverStone 700W SFX 80 Plus Gold Power Supply
The SilverStone 700W SFX 80 Plus Gold Power Supply stays within the SFX form factor, making it a direct size-compatible alternative. It offers 700 watts, which is 50 watts more than the GAMEMAX GS Series. It shares the fully modular design and 80 Plus Gold efficiency rating. The key difference is the focus on quiet operation and Japanese capacitors, which may appeal to users prioritizing silence and component longevity. It fits in the same small cases as the original. Choose this if you need slightly more power than 650W while maintaining a compact footprint and valuing silent performance in small form factor builds.
EVGA SuperNOVA 850 GM SFX Power Supply
The EVGA SuperNOVA 850 GM SFX Power Supply delivers 850 watts in an SFX form factor, providing 200 watts more than the GAMEMAX GS Series. It retains full modularity and 80 Plus Gold efficiency, matching the original's performance class. The primary advantage is the 10-year warranty, which offers longer protection than the standard warranty periods often found in this category. It is slightly larger in width than typical SFX units, so check case clearance. This option suits users who need high wattage in a compact size and want extended warranty coverage for their investment.
Quick picks
Our 7 picks
GAMEMAX GS Series 650W SFX PSU
Best for: compact SFX cases needing efficient power
- Wattage
- 650W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Full Modular
- Form Factor
- SFX
This GAMEMAX unit is a 650W power supply designed for small form factor builds. It features an SFX form factor and 80 Plus Gold efficiency rating. The fully modular design lets you connect only the cables you need, reducing clutter inside tight cases. You get reliable power delivery for mid-range components without excess waste. It fits well in compact chassis that require smaller PSUs.
Pros
- 650W output capacity
- 80 Plus Gold efficiency rating
- Fully modular cable design
- Compact SFX form factor
Cons
- Lower wattage than 750W or 850W alternatives on this list
- SFX size may limit airflow in densely packed cases
- No mention of zero-RPM fan mode for silent operation
Good fit if
- You are building in a small form factor case
- You need 80 Plus Gold efficiency for lower heat
- You want fully modular cables for clean builds
Skip if
- You require more than 650W of power
- You are using a standard ATX mid-tower case
- You need high-end components drawing over 650W
Verdict: GAMEMAX 650W SFX Gold PSU is a solid choice for compact builds needing efficient power. It suits users prioritizing size and efficiency over maximum wattage headroom.
GAMEMAX 850W SFX Gold Power Supply
Best for: high-density SFX builds
- Wattage
- 850W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Full Modular
- ATX Version
- ATX 3.0
- PCIe Connector Type
- 12VHPWR
- Form Factor
- SFX
This is a fully modular SFX power supply rated at 850W with 80 Plus Gold efficiency. It supports ATX 3.0 and includes a 12VHPWR connector for modern graphics cards. The unit uses Japanese capacitors and an FDB fan for quiet operation. It fits small form factor builds needing high power density and stable voltage under load.
Pros
- 80 Plus Gold efficiency rating
- 850W output capacity
- Includes 12VHPWR PCIe 5.0 connector
- Fully modular cable design
- ATX 3.0 compliant
Cons
- SFX form factor limits case compatibility
- No mention of zero-RPM fan mode
- Brand reliability less established than Corsair or Silverstone
Good fit if
- You need 850W in a small SFX case
- You want full modularity for clean builds
- You require native 12VHPWR support
Skip if
- You require an ATX form factor
- You need a 1000W or higher rating
- You prefer a brand with longer market history
Verdict: GAMEMAX SFX 850W Gold PSU delivers high wattage in a compact chassis for small builds. It suits users prioritizing density and modern PCIe 5.0 support over brand prestige.
Corsair RM850x Shift 850W White ATX Power Supply
Best for: Standard ATX cases needing PCIe 5.1 support
- Wattage
- 850W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- PCIe Connector Type
- PCIe 5.1
- Dimensions
- 6.3 × 5.91 × 3.39 inches
View on Amazon: Corsair RM850x Shift 850W White ATX Power Supply
This Corsair unit delivers 850W of power in a standard ATX form factor. It features full modularity and 80 Plus Gold efficiency. The build supports ATX 3.1 and PCIe 5.1 standards. Zero RPM mode keeps it silent at low loads. It suits users who need modern connector support in a reliable, fully modular design.
Pros
- 850W continuous power output
- Fully modular cable design
- 80 Plus Gold efficiency rating
- Supports ATX 3.1 standard
- Includes PCIe 5.1 connectors
Cons
- Standard ATX size limits use in small form factor cases
- Heavier at 3.75 pounds compared to SFX units
- Larger dimensions than compact alternatives
Good fit if
- You need ATX 3.1 compatibility for new GPUs
- You prefer fully modular cables for clean builds
- You want 80 Plus Gold efficiency
Skip if
- You are building in a small form factor case
- You require an SFX power supply
- You need a compact, lightweight unit
Verdict: Corsair RM850x Shift 850W ATX PSU fits users needing modern ATX 3.1 and PCIe 5.1 support in a standard case. It is not suitable for small form factor builds.
Corsair RM750x Shift White 750W ATX Power Supply
Best for: Standard ATX builds needing side-mounted connectors
- Wattage
- 750W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- Fan Size
- 140mm
- PCIe Version
- PCIe 5.1
View on Amazon: Corsair RM750x Shift White 750W ATX Power Supply
The Corsair RM750x Shift is a 750W fully modular ATX power supply with 80 Plus Gold efficiency. It features side-mounted modular connectors for easier cable management and uses Type 5 Gen 1 micro-fit cables. The unit includes a 140mm fan and Japanese electrolytic capacitors. It suits builders needing clean cable routing and modern ATX 3.1 compliance.
Pros
- Side-mounted modular connections for easier access
- Fully modular with Type 5 Gen 1 micro-fit connectors
- 140mm fluid dynamic bearing fan
- ATX 3.1 and PCIe 5.1 certified
Cons
- ATX form factor does not fit small SFX cases
- Heavier at 3.75 pounds compared to SFX units
- Larger dimensions than compact alternatives
Good fit if
- You need side-mounted modular connectors for cleaner cable management
- You are building in a standard ATX case
- You want ATX 3.1 and PCIe 5.1 support
Skip if
- You are building in a small form factor case requiring SFX
- You need a power supply under 3 pounds
- You require a compact 5-inch width
Verdict: Corsair RM750x Shift 750W ATX is ideal for standard ATX builds where side-mounted connectors simplify cable management. It is not suitable for compact cases requiring SFX form factors.
Corsair RM1000e 1000W ATX Power Supply
Best for: Standard ATX cases needing high wattage
- Wattage
- 1000 Watt
- Efficiency Rating
- 80 PLUS Gold
- Modularity
- Fully Modular
- Form Factor
- ATX
- Size
- 1000W
- Dimensions
- 5.91 × 5.51 × 3.39 inches
This Corsair unit delivers 1000W of power in a standard ATX form factor. It features full modularity for clean cable management and 80 PLUS Gold efficiency. The dual EPS12V connectors support high-end CPUs. Its low-noise design suits users who prioritize quiet operation. It is a robust option for systems requiring significant power headroom.
Pros
- 1000W output capacity
- Fully modular cable design
- 80 PLUS Gold efficiency rating
- Dual EPS12V connectors
Cons
- ATX form factor does not fit SFX cases
- Heavier build at 3.66 pounds
- Larger physical dimensions than SFX units
Good fit if
- You need high wattage for a standard ATX case
- You want fully modular cables for tidy builds
- You require dual EPS connectors for modern CPUs
Skip if
- You are building in an SFX or SFX-L case
- You need a compact power supply for small form factor builds
- You prefer a lighter unit for portable setups
Verdict: Corsair RM1000e 1000W ATX PSU fits users with standard ATX cases who need reliable high-wattage power and quiet operation. It is not suitable for compact SFX builds.
SilverStone 700W SFX 80 Plus Gold Power Supply
Best for: Silent SFX builds requiring 700W
- Wattage
- 700W
- Efficiency Rating
- 80 PLUS Gold
- Modularity
- Fully Modular
- Fan Size
- 92mm
- Form Factor
- SFX
- Dimensions
- 4.92 × 3.94 × 2.5 inches
View on Amazon: SilverStone 700W SFX 80 Plus Gold Power Supply
This SilverStone unit delivers 700W of power in a standard SFX form factor. It features full modularity and 80 PLUS Gold efficiency. The 92mm fan supports silent operation down to 18 dBA. All Japanese capacitors ensure stable performance. It suits users who need high efficiency in a compact case without ATX compatibility.
Pros
- 700W output capacity
- 80 PLUS Gold efficiency rating
- Fully modular cable design
- 92mm fan with 18 dBA silent running
- All Japanese capacitors for stability
Cons
- Not compatible with ATX mounting holes
- Heavier at 3.09 pounds
- Single +12V rail limits multi-rail flexibility
Good fit if
- You need a compact SFX power supply
- You prioritize silent operation under 20 dBA
- You want full modularity for clean builds
Skip if
- You require ATX form factor compatibility
- You need more than 700W of power
- You prefer a lighter power supply
Verdict: SilverStone SST-SX700-G 700W SFX Gold is a reliable choice for small form factor builds that demand high efficiency and quiet operation. It fits users who value Japanese capacitors and silent fans over ATX compatibility.
EVGA SuperNOVA 850 GM SFX Power Supply
Best for: Users needing 850W and a 10-year warranty
- Wattage
- 850W
- Efficiency Rating
- 80 PLUS Gold
- Modularity
- Fully Modular
- Warranty
- 10 Year
- Form Factor
- SFX
- Dimensions
- 4.92 × 4.92 × 2.48 inches
The EVGA SuperNOVA 850 GM is an 850W SFX power supply with 80 Plus Gold efficiency. It features a fully modular design and uses Japanese capacitors for reliability. The unit includes an FDB fan and ECO mode. It also supports ATX form factor with a bracket. This unit offers a 10-year warranty, which is longer than most competitors in this guide.
Pros
- 850W output capacity
- 80 Plus Gold efficiency rating
- 10-year warranty coverage
- Fully modular cable design
- Includes ATX mounting bracket
Cons
- Heavier at 4 pounds
- Larger dimensions than standard SFX
- No mention of low-noise mode beyond ECO
Good fit if
- You need 850W in an SFX case
- You want a 10-year warranty
- You plan to use the ATX bracket
Skip if
- You need the smallest SFX footprint
- You prefer a lighter unit
- You do not need 850W
Verdict: EVGA SuperNOVA 850 GM SFX PSU fits users who need high wattage and a long warranty in a compact form factor. It is a solid choice for high-end builds where space allows for its slightly larger size.
Specifications side by side
| Spec | GAMEMAX GS Series 650W SFX PSU | GAMEMAX 850W SFX Gold Power Supply | Corsair RM850x Shift 850W White ATX Power Supply | Corsair RM750x Shift White 750W ATX Power Supply | Corsair RM1000e 1000W ATX Power Supply | SilverStone 700W SFX 80 Plus Gold Power Supply | EVGA SuperNOVA 850 GM SFX Power Supply |
|---|---|---|---|---|---|---|---|
| Wattage | 650W | 850W | 850W | 750W | 1000 Watt | 700W | 850W |
| Efficiency Rating | 80 Plus Gold | 80 Plus Gold | 80 Plus Gold | 80 Plus Gold | 80 PLUS Gold | 80 PLUS Gold | 80 PLUS Gold |
| Modularity | Full Modular | Full Modular | Fully Modular | Fully Modular | Fully Modular | Fully Modular | Fully Modular |
| ATX Version | not specified | ATX 3.0 | ATX 3.1 | ATX 3.1 | not specified | not specified | not specified |
| PCIe Connector Type | not specified | 12VHPWR | PCIe 5.1 | not specified | not specified | not specified | not specified |
| Fan Size | not specified | not specified | not specified | 140mm | not specified | 92mm | not specified |
| Warranty | not specified | not specified | not specified | not specified | not specified | not specified | 10 Year |
| Form Factor | SFX | SFX | ATX | ATX | ATX | SFX | SFX |
| PCIe Version | not specified | not specified | PCIe 5.1 | PCIe 5.1 | not specified | not specified | not specified |
| Size | not specified | 850W | 850W | 750W | 1000W | 700W | 850W |
| Dimensions | not specified | not specified | 6.3 × 5.91 × 3.39 inches | 6.3 × 5.91 × 3.39 inches | 5.91 × 5.51 × 3.39 inches | 4.92 × 3.94 × 2.5 inches | 4.92 × 4.92 × 2.48 inches |
| Weight | not specified | not specified | 3.75 pounds | 3.75 pounds | 3.66 pounds | 3.09 pounds | 4 pounds |
| Color | not specified | WHITE | White | White | Black | Black?Lead-Free Paint? | not specified |
| Model | not specified | not specified | not specified | CP-9020273-NA | not specified | SST-SX700-G | 123-GM-0850-X1 |
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Frequently asked questions
Is the GAMEMAX GS Series 650W SFX fully modular?
Yes, the GAMEMAX GS Series 650W SFX is fully modular. This means you connect only the cables you need, reducing clutter in small cases. It also features 80 Plus Gold efficiency for reliable power delivery in compact builds.
Can I use the Corsair RM850x Shift in a small SFX case?
No, the Corsair RM850x Shift is an ATX power supply. It is designed for standard ATX cases and is not suitable for small form factor builds that require the compact SFX dimensions. It does not fit in SFX chassis.
Does the GAMEMAX 850W SFX support PCIe 5.0?
Yes, the GAMEMAX 850W SFX Gold Power Supply supports modern PCIe 5.0. This allows it to handle high-end graphics cards that require the latest power standards while maintaining a compact form factor for dense small builds.
What is the warranty on the EVGA SuperNOVA 850 GM SFX?
The EVGA SuperNOVA 850 GM SFX includes a 10-year warranty. This long coverage period provides peace of mind for high-end builds. It delivers 850W of power in a compact form factor suitable for users needing reliable long-term support.
Is the Corsair RM750x Shift suitable for SFX cases?
No, the Corsair RM750x Shift is an ATX power supply. It is intended for standard ATX builds where side-mounted connectors simplify cable management. It is not suitable for compact cases requiring the smaller SFX form factor.
Does the SilverStone 700W SFX use a quiet fan?
Yes, the SilverStone SST-SX700-G is noted for quiet operation. It is a reliable choice for small form factor builds that demand high efficiency and silent performance. It features 80 Plus Gold efficiency and fully modular cabling for clean installations.
What efficiency rating does the Corsair RM1000e have?
The Corsair RM1000e has an 80 Plus Gold efficiency rating. This ensures reliable power delivery and reduced energy waste. It is designed for standard ATX cases needing high wattage and quiet operation, rather than compact SFX builds.
Which GAMEMAX model offers the highest wattage in SFX form?
The GAMEMAX 850W SFX Gold Power Supply offers the highest wattage at 850W. It maintains the compact SFX form factor and fully modular design. This makes it ideal for high-density builds requiring more power than the 650W model.