The PSU or Power Supply Unit is what bringsevery component of a computerto life. As the name suggests, it relays power from the wall to the different components of a computer, depending on how much they require. There are a plethora of PSUs in the market in different price brackets with different efficiency ratings, more on that later. They can start at an expensive price and go up to thousands of dollars. But this also means there are multiple options to compare and choose from at every price point. This guide focuses on the budget segment with power supplies under $100.

EVGA 550 BP

Things to Consider When Buying a Power Supply

An efficient power supply is arguably the most important component of a PC because it has the potential to not only break but also damage other components in the process. So, investing in the right PSU iskey to any PC buildand there are a few things to consider before pulling the plug.

Wattage: The first thing to consider when looking at PSUs is the wattage or the maximum power it can deliver to the components. The beefier the system, the higher the wattage needs to be. A PSU needs to be able to supply a level of power that is sufficient for all components at max load. For example, if a system requires 350W-400W for all its components, it should be supported with at least a 400W PSU, but preferably one that goes a bit higher. Having some headroom is recommended in case of power spikes.

CORSAIR RM750x

Rating: Power supplies have 80 Plus ratings to help understand how efficient and reliable they are. There are six different ratings as explained later in this guide.

Form Factor: Depending on the form factor of the PC, a PSU can be ATX (fits all ATX PC cases), TFX (for mini or home-media PC), SFX (works with mini-ITX or even micro-ATX.), or SFX-L (micro-ATX and small form factor builds).

Cooler Master MWE Gold V2 power supply

Modularity: PSUs can be non-modular, semi-modular, or fully modular, depending on how the cables have been attached to them.

Game Rant’s Picks for the Best Power Supplies Under $100

Corsair RM750x Shift

CORSAIR RM750x Shift uses 100% Japanese capacitors and a bigger fan compared to the regular RM750 power supply. It’s 100% modular in design and is ATX 3.0 and PCI-E 5.0 Compliant as well, giving users all the necessary modern connectors to power their components.

The Corsair RM750X Shift is an upgraded version of the regular RM750, which now uses 100% Japanese capacitors rated at 105 degrees Celsius. With these highly reliable capacitors, the power supply can work under harsh conditions and has all the major protection features to save it and other components from damage. Unlike most power supplies under $100, the RM750X Shift brings a slightly different design, which incorporates the usage of smaller Corsair Type 5 Micro-Fit connectors that provide a lot of space for adding multiple ports to the PSU and make upgrading convenient.

Thermaltake Toughpower GF A3 750W power supply

Due to its fully modular design, the power supply doesn’t result in any cable clutter and has the latest PCI-E 5.0 12VHPWR connector as well. This will be beneficial for the current-genhigh-end RTX 40 series GPUsas well as future GPUs using the same connector. The hold-up time, voltage regulation, and efficiency are excellent and make it the best overall PSU to consider for under $100.

Cooler Master MWE Gold 850 V2

The Cooler Master MWE Gold 850 V2 is a full-size ATX PSU rated for 850W and it has an 80 Plus Gold rating. It is a fully modular offering with 2 EPS connectors that ensure compatibility with all current-gen motherboards. It features a 120mm HDB or hydro dynamic bearing fan with quiet operation. The Cooler Master MWE GOLD 850 - V2 comes with 1 ATX 24-pin connector, 1 EPS 4+4-pin connector, 1 EPS 8-pin connector, 12 SATA connectors, 4 peripheral 4-pin connectors, and 4 PCI-e 6+2-pin connectors.

Offering the most for the budgetis the Cooler Master MWE GOLD 850 - V2. It is a fully modular PSU capable of 850W of power, and it comes with an 80 Plus Gold efficiency rating, a combination that is rare in the below $100 range. The company states that due to legislation for 80 Plus Gold ratings to become the minimum level, it wants to bring more affordable options for people. The V2 comes with two EPS connectors that ensure compatibility with all current-gen motherboards and also raise the maximum operating temperature by 5 degrees compared to the V1.

MSI MAG A850GL

There is a 120mm HDB or hydro dynamic bearing fan that operates at very low RPM up to 50% load. It has the typical protection measures like OVP, OPP, OTP, SCP, OCP, and UVP built in. The Cooler Master MWE GOLD 850 - V2 is a full-size ATX PSU that features one ATX 24-pin connector, one EPS 4+4-pin connector, one EPS 8-pin connector, 12 SATA connectors, four peripheral 4-pin connectors, and four PCI-e 6+2-pin connectors. The Cooler Master MWE GOLD 850 - V2 has an MTBF of over 100,000 hours making it reliable and durable.

Thermaltake Toughpower GF A3 750W

The Thermaltake Toughpower GF A3 750W power supply is a fully modular offering in the long-running Toughpower series. It is an 80-Plus Gold-rated PSU with peak power of 750W, which is sufficient even for most high-end PCs. It features a PCIe Gen 5.0 connector to power GPUs with the new 12VHPWR cable. It also follows the ATX 3.0 standard for better power excursion and low-load efficiency. The 120mm fan has a Smart Zero Fan mode for silent operation.

Thermaltake has been making power supplies for over 15 years and the Toughpower series is one of its long-running product lines. The 750W Toughpower GF A3 PSU comes with an 80 Plus Gold rating making it very reliable and efficient. It is an ATX power supply with a fully modular design allowing for easy cable management and the ability to have custom cables.

Thermaltake Toughpower GX2

What’s unique about the Thermaltake Toughpower GF A3 750W PSU is that it is fully compatible with Intel ATX 3.0 specifications which brings the PCIe Gen 5.0 12VHPWR 16-pin connector. This connector can deliver up to 600W of power for PCIe 5.0 graphics cards which,as seen in the case of the RTX 4090, has become a necessity. The PSU comes with all the standard protection built in including OCP (Over Current Protection), OVP (Over Voltage Protection), OPP (Over Power Protection), SCP (Short Circuit Protection), and more.

Another unique feature of the Toughpower GF A3 750W is that the 120mm fluid bearing fan uses the company’s Smart Zero Fan tech which keeps the fan idle up to 30% load. It also has an MTBF of over 100,000 hours. The PSU comes with one 24-pin connector, four PCI-E 6+2-pin connectors, one PCI-E 12+4-pin (12VHPWR), two ATX 12V 4+4-pin connectors, eight SATA connectors, and an FDD adapter.

EVGA 550 BP

MSI MAG A850GL

MSI MAG A850GL boasts a fully modular design with several connectors to power a mid-range or high-end PC. It’s PCI-E 5.0 compliant and is among the first ones to provide a yellow-tipped 12VHPWR power connector to avoid connector melting. With 850W of reliable and stable power, it can power even the flagship Nvidia and AMD GPUs.

The popular 12-pin power connector melting problem on the RTX 4090 has damaged dozens of cards, and even today, such incidents haven’t stopped appearing on social media websites such as Reddit. By design, the 12VHPWR connector can melt easily even when users might think they have inserted the connector properly. To avoid this problem altogether, MSI brought a Yellow-Tipped 12-pin connector to make sure users can fully insert their connectors into the PSU port. This is a crucial stepfor RTX 4090 usersand the MSI A850GL is designed to do exactly that.

With a fully modular design, multiple connectors for various components, and 850W of reliable power delivery, this PSU unit is an impressive choice for under $100. The PSU features an 80 Plus Gold-rated efficiency and brings various heavy-duty protection measures. Furthermore, the 2x Power Excursion feature can provide up to 1700W of wattage for 100 milliseconds when needed. The PSU might get a little noisier in prolonged usage, but apart from this, it’s a fantastic budget power supply for high-end graphics cards.

Thermaltake Toughpower GX2 600W

Thermaltake Toughpower GX2 600W is a highly affordable GPU with excellent power efficiency. Its 600W capacity is sufficient for most budget or even mid-range builds and this PSU makes sure users get all the needed cables for their components. The GX2 comes with a 5-year warranty and various protection features to keep the components safe.

The Toughpower GX2 aged well, and it has dropped in price significantly since its launch. The GX2 600W is still selling like hotcakes as it offers an 80 Plus Gold rating on a budget. While the wattage capacity isn’t very high, it should still be sufficient forbuilding a budget gaming PCwith somethinglike an RTX 4060or even RX 7800 XT that will work pretty decently. The unit uses high-quality components and provides a powerful 12V+ rail to keep up with the demands. The voltage regulation is also satisfactory on different rails, but it can’t be compared with some modern PSUs listed previously.

Since it’s non-modular, it comes with mustard and colored cables that, even though might look unappealing, are covered with a sleeve for extra protection. It is equipped with several protection features, such as OPP, OVP, UVP, and SCP to ensure flawless operation, protecting the PC components all the time. All in all, this isn’t a regular budget but a fantastic PSU that has no competition for its price point.

EVGA 550 BP is an ultra-compact PSU for compact systems, providing 550W of capacity and an 80 Plus Bronze rating for over 85% power efficiency on typical loads. Being compact doesn’t limit it from performing well under different loads, and it is quieter since it uses an HDB fan. The PSU comes with a 3-year warranty.

The EVGA 550 BP is yet another outstanding unit that offers an ultra-quiet operation. This time, however, it also provides a smaller build that can fit into manyMini-ITX cases. With an 80 Plus Bronze rating, the PSU can provide over 85% power efficiency on typical loads and maintains 80% efficiency even on full load as well.

While 550 wattage capacity isn’t sufficient to power up an RTX 4090, it surely can power mostbudget graphics cardswith some room for additional upgrades. Adding another storage drive or two, or even a few chassis fans won’t be a big deal and the same goes for the CPUs except if the next upgrade is the Core i9 14900K. The 550 BP is non-modular in design but has well-sleeved cables and has proved itself to be highly reliable to work for several years continuously. It’s cheap, power-efficient, and has good voltage regulation.

Understanding PSU Ratings

To categorize the efficiency and reliability of a PSU, manufacturers have an 80-plus rating system. This essentially means that every PSU that carries the 80 Plus rating will deliver at least 80% power efficiency, if not more when it is at 20, 50, and 100 percent load. For example, a PSU that draws 400W from the wall and supplies 320W to the PC has an efficiency of 80%. Another measure of efficiency is how much power goes back into the power supply itself compared to the power going out into your PC. Based on these principles, PSUs have six ratings, which are:

80 Plus Standard or 80 Plus White rating means a PSU can deliver 82% efficiency at 20% load, 85% at 50% load, and 82% at 100% load. These are pretty much extinct at this point as they don’t provide the necessary level of efficiency. 80 Plus Bronze rating means 85% efficiency at 20% load, 88% at 50, and 85% at 100. The Silver rating signifies 87%, 90%, and 87% efficiency respectively. Similarly, Gold stands for 90%, 92%, and 89% while Platinum signifies 92%, 94%, and 90%. 80 Plus Titanium rating is given to PSUs that can deliver 94%, 96%, and 94% efficiency at 20, 50, and 100% load respectively. Furthermore, it also delivers 90% efficiency at 10% load, a feat that none of the other PSUs can achieve.

Form Factor: The size of the power supply is also a key consideration. There are four main sizes that PSUs are available in – ATX, TFX, SFX, or SFX-L. Those building in standard-sized ATX PC cases can use most of the PSU sizes while those working with small form factor PCs can only use SFX or SFX-L PSUs.

Modularity: A non-modular PSU is one where all cables are soldered to the board. While these may work with the most basic window-less PCs, managing all cables can be a nightmare. There is no way of getting rid of cables that are not being used. A semi-modular PSU, as the name suggests, is one where the main cables like the 24-pin, 8-pin, and PCIe cables are all connected to the board. The SATA cables and extra PCIe cables are left up to the user to connect as their build demands. Modular PSUs, on the other hand, have none of the cables connected to the board which allows for much easier cable management and customization.

FAQ

Q: What PSU should I get for RTX 4090?

Nvidia recommends a minimum 850W PSU for its powerful RTX 4090 graphics card.

Q: It is okay to buy a cheap PSU?

“Cheap” is a subjective measure and can include a range of budgets for different people. There are plenty of great budget friendly PSUs as mentioned in this guide. ensure to check the specifications like capacity, 80 Plus rating, form factor, and modulatory of the PSU before making the purchase.

Q: What is the best PSU under $100?

As per the specifications and price point, the Cooler Master MWE GOLD 850 - V2 is the best overall PSU under $100.