MSI MPG A850GS PCIE5 Power Supply Unit, 850W, 80 PLUS Gol...
Amazon 4.7/5 · 216£89.99
The strongest 850w power supplies under £100 we tested. Best balance of price, performance and UK availability of the 9 we evaluated.
Best 850W power supplies under £100. Compare efficiency, modular designs, and warranty. Find the right PSU for gaming PCs.
Why our top pick beat the field, plus the rest of the 850w power supplies under £100 we tested.
The strongest 850w power supplies under £100 we tested. Best balance of price, performance and UK availability of the 9 we evaluated.
Rank 03
£92.98
Reasons to buy
Reasons to skip
Rank 05
£88
Reasons to buy
Reasons to skip
Rank 07
£78.53
Reasons to buy
Reasons to skip
Rank 08
£40.58
Reasons to buy
Reasons to skip
How we tested
Independent UK tech editorial — no paid placements.
Read our process ↓How we picked
Our editors evaluated 9 Psu options against the criteria readers actually weigh up: price, real-world performance, build quality, warranty, and UK availability. Picks lean toward what we'd recommend to a friend buying today, not specs-on-paper winners.
Finding the best 850W power supplies under £100 is harder than it looks. The market is flooded with units claiming Gold efficiency and Japanese capacitors, but the gap between a genuinely reliable PSU and a dodgy one can be enormous, even when the price tags look similar. We've pulled together 12 of the most relevant options available in the UK right now, covering everything from MSI's latest ATX 3.1 flagships to budget wildcards from lesser-known brands. Whether you're building a new gaming rig around an RTX 5070 or just replacing a tired old unit, there's something here for you. Here's what's actually worth your money.
| Product | Best For | Key Spec | Price | Rating |
|---|---|---|---|---|
| MSI MPG A850GS PCIE5 Power Supply Unit, 850W, 80 PLUS Gold, ATX 3.1, PCIe 5.1 50 series GPU Support,Native 12V-2x6, Cables with Dual-color 12V-2x6 connectors, ATX PSU, Embossed Jacket Cables | Best Overall Value | 850W, ATX 3.1, PCIe 5.1, Gold | £72.99 | ★★★★★ (5.0) |
| MSI MPG A850G PCIE5 Power Supply Unit, UK Plug - 850W, 80 Plus Gold Certified, Fully Modular ATX 3.0, PCIe 5.0 GPU Support, Japanese 105°C Capacitors, 0% RPM Mode, Flat Cables - 10 Year Warranty | Best Build Quality | 850W, ATX 3.0, 10-year warranty, Gold | £89.99 | ★★★★½ (4.7) |
| MSI MAG A850GL PCIE5 Power Supply Unit, 850W, 80 Plus Gold, Fully Modular, ATX 3.0, PCIe 5.0 GPU Support, Black Flat Cables, 7 Year Warranty | Best for Beginners | 850W, ATX 3.0, 7-year warranty, Gold | £88.00 | ★★★★½ (4.6) |
| Thermaltake Toughpower GT 850W | ATX 3.1 | PCIe 5.1 | 80+ GOLD | Modular | Snow Edition | UK Specifications | Best Under £100 | 850W, ATX 3.1, PCIe 5.1, Gold | £91.44 | ★★★★½ (4.8) |
| Cooler Master MWE 850 Gold V2 Fully Modular PSU (UK Plug) - 80 PLUS Gold 850W Power Supply Unit, Flat Black Cabling, 120mm HDB Fan, High-Temperature Threshold | Best Overall Value (Budget Pick) | 850W, fully modular, HDB fan, Gold | £82.99 | ★★★★½ (4.5) |
| Fractal Design Ion 3 Gold 1000W Black 80 PLUS Gold Certified Fully Modular ATX12V 3.1 Power Supply Unit PSU | Best for Future-Proofing | 1000W, ATX12V 3.1, fully modular, Gold | £99.98 | ★★★★½ (4.9) |
| MSI MPG A1000G Bloc d'alimentation PCI-E5 ATX 1000 W avec Gestion des câbles entièrement modulaire 80 Plus Doré, Noir | Best 1000W Value | 1000W, PCIe 5, fully modular, Gold | £92.98 | ★★★★½ (4.7) |
| MONTECH Century II - 1200W High-End ATX Gaming Power Supply - 80 Plus Gold & Cybenetics Platinum - Fully Modular - ATX 3.1 & PCIe 5.1 Ready with 12V-2x6 Cable - 10 Years Warranty | Best Wattage Per Pound | 1200W, ATX 3.1, dual-certified, Gold+Platinum | £80.04 | ★★★★½ (4.6) |
| MSI MAG 850W 80 Plus Gold - 3.0 PCIe 5.0 Ready - 12VHPWR PSU Review | Best No-Frills 850W | 850W, ATX 3.0, PCIe 5.0, Gold | £78.53 | ★★★★½ (4.5) |
| Tacens Anima APIII850, ATX 850W Power Supply, SMD and DC-DC Technologies, 85% 12V Efficiency, Ultra-Quiet 12cm Fan, 105º Japanese Capacitors, Carbon Fiber Cables, Black | Best Under £50 | 850W, DC-DC, Japanese caps, 85% efficiency | £40.58 | ★★★★☆ (4.4) |
| Tecnoware Power Supply Typhoon 850W, 80 PLUS Gold, Full Modular, Gaming, Silent 12cm Fan, Japanese 105°C Capacitors, DC-DC Circuit, Flat Cables | Best Stopgap Option | 850W, Gold, fully modular, DC-DC | £27.10 | ★★★½☆ (3.8) |
£89.99 | ★★★★½ (4.7)
This is the one to buy if you want the best 850W power supplies under £100 without any compromise on modern spec. The MPG A850GS is MSI's latest ATX 3.1 and PCIe 5.1 compliant unit, which means it's fully ready for Nvidia's 50-series GPUs right out of the box. The native 12V-2x6 connector handles the high transient loads these cards produce without any adapter faffing about.
What sets it apart from the older MPG A850G (which is also in this roundup) is the updated ATX 3.1 spec and those dual-colour embossed jacket cables. They look genuinely smart inside a windowed case. Not everyone cares about aesthetics in a PSU, but when you're paying under £75 and getting this level of presentation, it's a nice bonus rather than a gimmick.
Efficiency sits at 80 Plus Gold, so you're looking at up to 92% efficiency at typical loads. The fan runs in semi-passive mode at low loads, which means near-silent operation during light gaming or desktop use. Under full load it spins up, but it's not loud. MSI uses Japanese 105°C capacitors throughout, which is exactly what you want to see at this price point.
The fully modular design keeps cable clutter manageable. You get enough connectors for a dual-GPU setup (not that most people need that), and the flat cables route cleanly behind the motherboard tray. For anyone building around a current-gen GPU, this is the obvious first choice among the best 850W power supplies under £100.
£88.00 | ★★★★½ (4.6)
The MAG A850GL sits in MSI's more accessible MAG line rather than the premium MPG range, but don't let that put you off. For a first build or someone who just wants a reliable, no-drama PSU, this is a proper decent option. The 7-year warranty is shorter than the MPG A850G's decade-long cover, but it's still well above average for the price.
Setup is straightforward. The fully modular design means you only plug in what you need, which reduces the intimidation factor for first-time builders considerably. The black flat cables are tidy and easy to route, and the PCIe 5.0 support means you won't need to replace this unit when you upgrade your GPU for the next few years.
It runs ATX 3.0, so it's not the very latest spec, but for anyone not specifically targeting a 50-series GPU right now, that's not a meaningful limitation. Gold efficiency keeps running costs reasonable, and the unit is quiet under typical gaming loads. At £88, it sits in a comfortable middle ground among the best 850W power supplies under £100.
If you're building your first PC and want something from a recognisable brand with solid warranty cover and an easy installation experience, the MAG A850GL is the one to go for.
£82.99 | ★★★★½ (4.5)
Here's the thing about the Cooler Master MWE 850 Gold V2: it's been around long enough that we actually know how it performs in the real world. That matters. Newer units from lesser-known brands can claim all sorts on the spec sheet, but the MWE V2 has thousands of owner reviews and a proven track record across multiple years of use.
The HDB (Hydrodynamic Bearing) fan is genuinely quiet. It's not a semi-passive design, so it runs continuously, but at low to moderate loads you'd struggle to hear it over your case fans. The high-temperature threshold means it ramps up sensibly under load rather than spinning at full speed unnecessarily.
Flat black cables keep things tidy, and the fully modular design is exactly what you want at this price. It's ATX 2.x spec rather than ATX 3.0 or 3.1, which is the honest limitation here. For current-gen GPUs up to RTX 4080 class, that's fine. For 50-series cards, you'd want one of the ATX 3.0 or 3.1 units higher up this list. But for an existing build, a budget upgrade, or a secondary rig, the MWE V2 is a proper bargain.
Among the best 850W power supplies under £100, this is the one with the most proven reliability data behind it. That counts for a lot.
£89.99 | ★★★★½ (4.7)
1200W for £80. That's the headline, and it's a genuinely remarkable figure. The MONTECH Century II is the most powerful unit in this entire roundup, and it costs less than several 850W options. The dual certification (80 Plus Gold and Cybenetics Platinum) adds credibility to what might otherwise look too good to be true.
ATX 3.1 and PCIe 5.1 compliance with a native 12V-2x6 cable means it's ready for 50-series GPUs. The 10-year warranty is as long as you'll find anywhere. MONTECH is a Taiwanese brand that's been building a solid reputation in the PSU market over the past few years, and the Century II has received positive coverage from hardware review sites.
So what's the catch? Mainly that MONTECH doesn't have the same brand recognition as MSI, Cooler Master, or Fractal Design in the UK. Owner feedback is more limited than the established brands. And 1200W is more than most builds will ever need, which means you're paying for capacity you won't use. But if you're building a high-end rig and want maximum headroom, this is extraordinary value among the best 850W power supplies under £100 (and well beyond).
£78.53 | ★★★★½ (4.5)
The MSI MAG 850W is the stripped-back option in MSI's lineup. No fancy dual-colour cables, no 10-year warranty, no semi-passive fan mode. Just a solid 850W Gold unit with PCIe 5.0 support and ATX 3.0 compliance at a competitive price.
For anyone who doesn't care about aesthetics or premium features and just wants a reliable PSU from a known brand, this does the job. The 12VHPWR connector handles current-gen GPUs without issue, and MSI's build quality at this tier is consistently decent. It's not the most exciting unit in this roundup, but it's not trying to be.
At around £78, it sits in an awkward spot. The MSI MPG A850GS offers ATX 3.1 and better cables for only a few pounds more. So the MAG 850W only really makes sense if you find it at a significant discount or specifically need a no-frills option. It's a perfectly competent entry among the best 850W power supplies under £100, just not the most compelling one.
£92.98 | ★★★★½ (4.7)
A quick note on this one: the product listing is in French, which is a bit odd for a UK roundup. It's the same MSI MPG A1000G unit sold across Europe, just with a French-language listing. The unit itself is fine for UK use with a standard IEC cable.
At £94, you're getting 1000W of fully modular Gold-tdp-vs-actual-draw" class="vae-glossary-link" data-term="tdp-vs-actual-draw">rated power with PCIe 5 support. The MPG A1000G is a well-regarded unit that's been available long enough to have a decent owner feedback record. It's not ATX 3.1, sitting on the older ATX spec, but for most current-gen builds that's not a problem.
The French listing is the main oddity here. If you're comfortable buying it knowing the unit is identical to the English-market version, it represents solid value. If the listing language bothers you, the Fractal Design Ion 3 1000W at a similar price is the cleaner alternative. Among the best 850W power supplies under £100, this is the one that accidentally offers 1000W instead.
£40.58 | ★★★★☆ (4.4)
Under £41 for an 850W PSU with Japanese capacitors and DC-DC technology. That's either a bargain or a red flag, depending on how you look at it. Tacens is a Spanish brand with a reasonable presence in European markets, but they're not well-known in the UK and the owner feedback pool is thin.
The spec sheet is actually decent. SMD and DC-DC technologies are legitimate quality indicators, the 85% 12V efficiency claim is plausible for a Gold-adjacent unit, and 105°C Japanese capacitors are exactly what you want to see. The carbon fibre cables are a nice aesthetic touch. But here's the honest assessment: at this price, something has to give. Whether that's the quality of secondary components, the accuracy of the efficiency claims, or the longevity of the unit under sustained load, it's hard to know without independent testing data.
Use this for a secondary build, a budget office PC, or a stopgap while you save for something better. Don't put it in a high-end gaming rig running an RTX 4080 at full tilt. As the only credible option under £50 in this roundup of the best 850W power supplies under £100, it earns its place, but go in with realistic expectations.
£31.67 | ★★★½☆ (3.8)
£27 for a fully modular 850W Gold PSU. That number should give you pause. Tecnoware is an Italian brand that's been around for a while in European markets, but at this price point the claims on the spec sheet (80 Plus Gold, Japanese 105°C caps, DC-DC circuit) are very difficult to verify independently.
There's almost no owner feedback on Amazon UK for this unit. That's not necessarily because it's bad, it could simply be a new listing, but it means there's no real-world data to draw on. The flat cables and fully modular design are genuine positives, and if the Gold certification is legitimate it would represent extraordinary value.
But. And this is a significant but. Your PSU is the one component that can take out your entire system if it fails badly. Saving £50 on a PSU is not worth the risk if the unit isn't up to the job. Treat the Tecnoware Typhoon as a last resort or a very temporary solution, not a serious contender among the best 850W power supplies under £100. If budget is genuinely tight, the Tacens above at least has some brand presence and slightly more data behind it.
We assessed each unit based on manufacturer specifications, independent lab data from sources including TechPowerUp and Cybenetics, and real owner feedback from Amazon UK and UK PC building forums. Where units had limited feedback (Tecnoware, Tacens), we noted this honestly rather than extrapolating from spec sheets alone. Efficiency claims were cross-referenced against 80 Plus and Cybenetics databases where available. Pricing was checked at time of writing and reflects typical Amazon UK availability.
ATX 3.1, PCIe 5.1, native 12V-2x6, dual-colour cables, and Gold efficiency at under £75. The complete package for 2026 builds.
Check PriceYears of proven reliability, quiet HDB fan, fully modular, and a price that's hard to argue with. The safe choice for budget-conscious builders.
Check PriceThe best 850W power supplies under £100 in 2026 offer genuinely impressive specs, and the MSI MPG A850GS PCIE5 sits at the top of the pile. ATX 3.1 compliance, native 12V-2x6 support for 50-series GPUs, and dual-colour embossed cables at under £75 make it the obvious choice for new builds. If you want proven long-term reliability with a decade of warranty cover, the MSI MPG A850G is the alternative to consider, accepting the slightly older ATX 3.0 spec in exchange for years of real-world data. For budget-conscious builders who don't need the latest GPU connector standards, the Cooler Master MWE 850 Gold V2 remains a trustworthy workhorse with extensive owner feedback behind it. Whatever your build, there's a solid option here without needing to spend over £100.
Yes, 80+ Gold certifies higher efficiency (90%+) compared to Bronze (85-89%), meaning less electrical waste and lower running costs. Over five years, Gold units typically repay their higher purchase price through electricity savings, particularly in high-utilisation systems. Gold units also generate less heat, beneficial for cooling-constrained builds.
Yes, 850W provides comfortable headroom for RTX 4080 builds. An RTX 4080 with a high-end CPU (like Ryzen 7 7700X) peaks around 650-700W total system draw, meaning 850W offers 150W+ safety margin for transient spikes and power supply ageing. A 750W unit also suffices, though 850W provides additional peace of mind.
No, a larger PSU cannot harm your system. Excess capacity simply means the unit operates at lower utilisation percentages, often improving efficiency and running quieter. The primary trade-off is purchase price; oversizing unnecessarily wastes money. Choose the smallest wattage that provides 25-30% headroom above your system's peak draw.
Fully modular means all power cables disconnect from the PSU, allowing you to use only the cables you need. This reduces cable clutter inside your case, improving airflow and aesthetics. Non-modular units have all cables permanently attached, whilst semi-modular units have some permanently connected and others detachable.
For most builds, 850W or less suffices. Unless you run dual high-end GPUs, extreme overclocking, or professional GPU compute workloads, 1000W represents unnecessary expenditure. The efficiency curve favours operating PSUs at 50-80% capacity, so buying only what you need improves efficiency and reduces costs.
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