MONTECH Century II - 850W High-End ATX Gaming Power Supply - 80 Plus Gold & Cybe vs JUSTOP Black 700W Power Supply Unit ATX PSU With 120MM Quiet Fan
Updated August 2026 — The MONTECH Century II is the superior choice for high-performance needs, while the JUSTOP Black offers a budget-friendly option for standard builds.
The MONTECH Century II is the superior choice for high-performance needs, while the JUSTOP Black offers a budget-friendly option for standard builds.
Why MONTECH Century II - 850W High-End ATX Gaming Power Supply - 80 Plus Gold & Cybe is better
Power Output
850W vs 700W
Efficiency
80 Plus Gold vs 70%
Modularity
Fully modular vs non-modular
Why JUSTOP Black 700W Power Supply Unit ATX PSU With 120MM Quiet Fan is better
Price
£29.95 vs £80.04
Cooling
120mm quiet fan
Safety Features
Multiple protections listed
Overall score
Specifications
| Spec | MONTECH Century II - 850W High-End ATX Gaming Power Supply - 80 Plus Gold & Cybe | JUSTOP Black 700W Power Supply Unit ATX PSU With 120MM Quiet Fan |
|---|---|---|
| Power Output | 850W | 700W |
| Efficiency Rating | 80 Plus Gold | 70% |
| Modularity | Fully Modular | Non-Modular |
| Cooling Fan | Not specified | 120mm quiet fan |
| Safety Features | Standard protections | Multiple protections |
Dimension comparison
Price Comparison
The MONTECH Century II is priced at £80.04, while the JUSTOP Black 700W is significantly cheaper at £29.95. This stark difference in price highlights the potential investment value of each product based on their features and specifications. The MONTECH power supply is marketed as a high-end unit, boasting an 850W capacity and 80 Plus Gold certification, which generally indicates higher efficiency. In contrast, the JUSTOP, with a lower wattage of 700W and a 70% efficiency rating, caters to a more budget-conscious audience. Therefore, if you're looking for premium performance, the MONTECH might justify its higher price.
Power Output
The MONTECH Century II offers a robust 850W power output, making it suitable for high-performance gaming systems that require substantial power for graphics cards and other components. On the other hand, the JUSTOP Black provides 700W, which is adequate for most standard desktop setups but may limit users with more demanding systems. The difference of 150W in power output could impact system stability and performance, especially under heavy load. For users with high-end gaming rigs or those planning future upgrades, the MONTECH's higher capacity is a significant advantage.
Efficiency Ratings
Efficiency can greatly influence your overall energy costs and system performance. The MONTECH Century II boasts an 80 Plus Gold rating, indicating it operates at a minimum of 87% efficiency under typical load conditions. In contrast, the JUSTOP Black holds a 70% efficiency rating, suggesting that it may waste more energy as heat. This difference in efficiency can lead to higher electricity bills over time, especially in power-hungry systems. For users prioritising energy efficiency and long-term savings, the MONTECH Century II is the superior option.
Modularity
The MONTECH Century II is fully modular, allowing users to connect only the cables they need, which can significantly improve airflow and reduce cable clutter within a case. This feature is particularly beneficial for high-end builds where airflow is critical for performance and cooling. Conversely, the JUSTOP Black does not specify modular capabilities, implying a more traditional design where all cables are permanently attached. This could lead to excess cables that may hinder airflow and aesthetics. For those who value a clean and efficient build, the modularity of the MONTECH is a notable advantage.
Cooling Features
Cooling is essential for maintaining optimal performance and longevity of power supplies. The JUSTOP Black features a 120mm quiet cooling fan, which aids in maintaining lower noise levels during operation. However, the MONTECH Century II does not specify its cooling solutions, though its higher efficiency rating may suggest better thermal management. The emphasis on quiet operation in the JUSTOP is appealing for users seeking a quieter PC experience, but without detailed cooling specifications from MONTECH, it’s hard to draw direct comparisons. Users prioritising noise levels may lean towards the JUSTOP, while those focused on performance might prefer the MONTECH.
Safety Features
When it comes to safety features, both power supplies include essential protections. The MONTECH Century II includes industry-standard safety measures, ensuring reliable operation under various conditions. Meanwhile, the JUSTOP Black lists several protections such as over voltage protection, short circuit protection, and thermal overload cut-off protection. This robust safety framework makes the JUSTOP a reliable choice for basic builds. However, the MONTECH's additional certifications and longer warranty period enhance its credibility in high-stakes environments where power reliability is critical. Users with high-performance systems may find the MONTECH’s safety assurances more appealing.
Brand Reputation
Brand reputation plays a key role in consumer decisions. MONTECH has established itself as a brand focused on high-end gaming components, which may imply a commitment to quality and performance. The MONTECH Century II, with its premium features and certifications, aligns with this reputation. Conversely, JUSTOP is a less well-known brand but offers a budget-friendly option that may appeal to casual users or those building entry-level systems. While the MONTECH may be seen as a more prestigious choice, JUSTOP's affordability does not necessarily equate to poor quality. Consumers should weigh brand reputation against their specific needs and budgets.
Which should you buy?
Ultimately, the choice between the MONTECH Century II and the JUSTOP Black comes down to specific needs and budget considerations. If you are building a high-performance gaming rig that demands efficiency, stability, and future-proofing, the MONTECH Century II, with its 850W capacity and 80 Plus Gold certification, is the clear winner at £80.04. However, if you're looking for a cost-effective solution for a standard desktop PC build and are less concerned about high efficiency, the JUSTOP Black at £29.95 offers good value with adequate features for basic usage. Each product has its merits, so align your choice with your performance requirements and financial considerations.
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