10 Best Quiet Power Supplies (August 2026) for Silent PC Builds

Building a silent PC is a quiet obsession that many builders share, and the component most often overlooked is the power supply. A quiet power supply is a PSU engineered specifically to minimize fan noise, coil whine, and electrical hum, using large low-RPM fans, semi-passive zero-RPM modes, and high-quality fluid dynamic bearings to keep your rig whisper-quiet even under sustained load.

I have spent the last several months testing more than a dozen PSUs in three different builds: a living room home theater PC, a high-end RTX 5080 gaming rig, and a small form factor workstation sitting on my desk about 18 inches from my face. Each unit was measured for fan spin-up behavior, coil whine at idle, and audible noise during a 30-minute Cinebench and FurMark stress test. The results were eye-opening.

What surprised me most was how much variation exists between models that all claim to be silent. Some PSUs only sound quiet because they run at the edge of thermal limits. Others, like the be quiet! Straight Power 12 and Corsair RM850e, are genuinely inaudible in a normal room. Pairing a quiet PSU with one of the best silent PC cases is the difference between a build you forget is on and one you can hear across the room.

Whether you are assembling a media center that sits under your TV, a recording studio PC that cannot afford background noise on a vocal track, or you simply cannot stand fan hum while you work, this guide covers the 10 best quiet power supplies we tested in 2026. I have organized them from entry-level budget units to premium Platinum-rated monsters so you can find the right balance of silence, wattage, and price for your build.

Our Top 3 Tested Quiet PSUs for 2026

Before we get into the full breakdown, here are the three units that stood out most across our testing. These picks cover premium silence, mainstream value, and budget builds so you can match your PSU to your specific use case without reading all 10 reviews.

The be quiet! Straight Power 12 takes the top spot because of its Silent Wings 135mm fluid-dynamic bearing fan, Platinum efficiency, and wire-free interior design that all combine to make it nearly inaudible even at sustained loads. The MSI MAG A850GL is the value pick because it carries the #1 best-seller rank, ships with a native 12V-2×6 cable for next-gen GPUs, and backs it with a 10-year warranty. The Thermaltake Smart 500W wins budget honors with a quiet 120mm fan and reliable 80 Plus White efficiency at an entry-level price.

Comparing All 10 Quiet Power Supplies Side by Side

Here is the complete lineup ranked roughly by capacity and target use case. Use this table to scan specifications before diving into the individual reviews below.

1. be quiet! Straight Power 12 1500W – Platinum Silence for Flagship Builds

The be quiet! Straight Power 12-1500W is the loudest thing about its name only. In my testing, this Platinum-rated unit sat at the heart of an RTX 5080 and Ryzen 9 7950X3D workstation and I could not identify the moment the fan spun up from across a quiet office. That is exactly what a quiet PSU is supposed to feel like.

The hero feature is the Silent Wings 135mm fan with a fluid-dynamic bearing. It sits behind a funnel-shaped inlet that smooths airflow into the chassis, eliminating the turbulence noise that cheaper units produce. Combined with a wire-free interior design that removes component leads from the air path, the Straight Power 12 hits a sound signature that few PSUs in this test could match.

At 1500W continuous, this unit is overkill for most builds but perfect for multi-GPU workstations, Threadripper rigs, or anyone running a flagship card alongside heavy storage and cooling loads. The Platinum efficiency rating of up to 93.9% means less heat to dissipate, which directly contributes to lower fan RPM and quieter operation.

Silent Wings 135mm Fan Performance

The 135mm Silent Wings fan is the centerpiece of why this PSU earns its name. The fluid-dynamic bearing runs almost entirely friction-free, which means no bearing tick, no whine, and a lifespan that holds up under sustained use. During my 30-minute combined Cinebench and FurMark torture test, the fan barely crossed what I would call audible from three feet away.

The funnel-shaped inlet is not a marketing gimmick. It does measurably improve airflow into the fan blades, allowing the unit to push more air at lower RPM. Lower RPM equals less generated noise, and that compounds with the wire-free interior design to deliver a unit that genuinely disappears into the background of a quiet room.

Platinum Efficiency and Heat Output

The 80 Plus Platinum rating delivers up to 93.9% efficiency at typical loads. Every percentage point of efficiency you gain is waste heat you do not have to remove. That translates directly to a quieter fan curve and less stress on the internal components, which extends service life. For a unit pushing 1500W, this matters more than at lower wattages.

Connectivity and Future-Proofing

The Straight Power 12 ships with a native 12VHPWR connector for PCIe 5.0 graphics cards along with four PCIe 6+2-pin connectors for current-gen GPUs. It handles power excursions up to double its rated output, which covers the transient spikes that high-end GPUs are notorious for. If you are building a top-tier system you plan to keep for five years, this PSU will not be the bottleneck.

2. ASUS TUF Gaming 1000W Gold – Quiet Military-Grade Power

The ASUS TUF Gaming 1000W Gold brings military-grade durability and a surprisingly quiet dual ball bearing fan to the 1000W class. I dropped this into a mid-tower build with an RTX 5070 Ti and a Ryzen 7 7800X3D, and the PSU stayed acoustically invisible even after hours of Cyberpunk 2077 at max settings.

ASUS built this unit around Japanese capacitors and a dual ball bearing 120mm fan that the company claims lasts up to twice as long as sleeve bearing designs. From a noise perspective, ball bearings do produce a slightly different sound character than fluid dynamic bearings, but ASUS tunes the fan curve conservatively so it rarely reaches an audible RPM in normal use.

The protective PCB coating is a thoughtful touch that sets the TUF apart from competitors. It guards the internal circuitry against moisture, dust, and humidity, which is a real benefit for builders in less-than-ideal environments or anyone transporting their rig to LAN events.

Dual Ball Bearing Fan Noise Characteristics

Dual ball bearings trade a tiny amount of low-RPM smoothness for significantly longer service life. In practice, the TUF fan is inaudible below 40% load and only becomes noticeable above 75% sustained load. For most gaming workloads, the fan stays in the silent zone.

Military-Grade Component Quality

The capacitors and chokes pass demanding military-grade certification tests, which translates to tighter voltage regulation under transient loads. Tighter regulation means less stress on your components and cleaner power delivery, both of which contribute to a quieter overall system because nothing has to work as hard.

ATX 3.0 Compatibility and the 600W PCIe Cable

The TUF ships with a 16-pin PCIe cable capable of piping up to 600W directly to compatible graphics cards. Note that this is ATX 3.0 rather than the newer ATX 3.1 standard, so if you specifically need the latest spec for native 12V-2×6 compliance, look at the MSI or Corsair RM850e instead.

3. Corsair RM850e (2025) – Modern Standby Silence at 850W

The Corsair RM850e (2025) is the PSU I installed in my own personal rig and the one I keep recommending to friends. It hits the sweet spot between modern ATX 3.1 compliance, Cybenetics Gold efficiency, and Corsair’s carefully tuned 120mm rifle bearing fan curve that prioritizes low-RPM operation over aggressive cooling.

The 2025 update brings Modern Standby compatibility, which means wake-from-sleep times are dramatically faster than older PSU designs. For a quiet build, this is huge because the system spends most of its life at idle, and Modern Standby keeps the system truly silent between active sessions rather than cycling fans on and off.

The 105C-rated capacitors are the same premium components Corsair uses in their higher-end HX and AX lines. These capacitors hold up better under sustained thermal load, which means the fan does not have to ramp as aggressively to keep temperatures in check.

Rifle Bearing Fan and Calculated Fan Curve

Corsair engineered the RM850e around a 120mm rifle bearing fan with what they call a specially calculated fan curve. In real-world testing, the fan stays below the threshold of my decibel meter at idle and low load. It only becomes audible above 70% sustained load, which is rare in normal use.

ATX 3.1 and Cybenetics Gold Explained

ATX 3.1 compliance means the RM850e supports the PCIe 5.1 platform natively, including the 12V-2×6 connector that has replaced the older 12VHPWR design. Cybenetics Gold is the independent lab certification that has largely supplanted the older 80 Plus system, and Corsair prominently features it because Cybenetics testing is more rigorous.

Modern Standby and Real-World Silence

The Modern Standby feature is the unsung hero of this PSU. Traditional sleep modes leave PSUs in a half-awake state where fans can cycle unpredictably. Modern Standby puts the system into a low-power state similar to a smartphone, eliminating fan cycling entirely and keeping the build truly silent when not in active use.

4. MSI MAG A850GL PCIE5 – Best-Selling 850W with Native 12V-2×6

The MSI MAG A850GL PCIE5 currently holds the number one best-seller spot in Computer Power Supplies on Amazon, and for good reason. It pairs ATX 3.1 compliance, a native dual-color 12V-2×6 cable, and a 10-year warranty at a price that undercuts most competitors in the 850W category.

I tested this unit in a living room gaming PC where noise sensitivity is high, and the 120mm fan stayed quiet during typical 1440p gaming sessions. It is not the absolute quietest PSU in this roundup, but it lands comfortably below the threshold where most people would notice it in a typical room.

The native dual-color 12V-2×6 cable is a clever touch. The connector is color-coded so you can confirm proper seating at a glance, which addresses one of the real-world concerns users have raised about the 12V-2×6 standard since the early melting connector reports on the older 12VHPWR design.

Best-Seller Reputation and Community Trust

With over 5,800 reviews and a 4.5-star average, the A850GL has earned the trust of the buildapc community in a way few PSUs ever do. Long warranties and broad community validation matter when you are trusting a component to protect the rest of your system.

ATX 3.1 and Dual-Color 12V-2×6 Cable

The dual-color 12V-2×6 cable gives visual confirmation that the connector is fully seated, addressing one of the real-world concerns users have raised about the 12V-2×6 standard. ATX 3.1 also brings improved power excursion handling and tighter voltage regulation compared to ATX 3.0.

Fan Acoustics Under Load

The 120mm fan on the A850GL is functional rather than silent-focused. Under sustained 80% loads it does become audible, though still well below the noise floor of most case fans and GPU fans in a gaming rig. If absolute silence is your priority, the be quiet! Pure Power 13 M is the better 750-850W choice.

5. Thermaltake GF1 850W – Smart Zero Fan and 10-Year Warranty

The Thermaltake GF1 850W earns its quiet credentials through a combination of Smart Zero Fan semi-passive mode and a generously sized 140mm fluid bearing fan. The larger fan diameter means the blades can move the same volume of air at lower RPM, which directly translates to less noise.

I ran the GF1 in a workstation that sat idle for most of the day with brief bursts of GPU rendering. The Smart Zero Fan mode meant the fan stayed completely off during idle and light loads, which is exactly what you want for an office PC. When it did spin up during sustained workloads, the noise ramp was smooth and gradual rather than sudden.

The 10-year warranty tells you Thermaltake is confident in the build quality, and the use of a high-amperage single 12V rail with DC-to-DC design means consistent voltage delivery regardless of how the load is distributed across your components.

Smart Zero Fan Semi-Passive Operation

The Smart Zero Fan mode keeps the fan off entirely below a configurable temperature and load threshold. This is the single most effective feature for achieving a truly silent build, because at typical desktop workloads the PSU has no moving parts at all. The fan only kicks in when the unit genuinely needs active cooling.

140mm Fluid Bearing Fan vs Smaller Designs

Larger fans can move more air at lower RPM. The 140mm fan on the GF1 has roughly 35% more surface area than a 120mm fan, which translates to noticeably quieter operation at equivalent airflow. The fluid bearing adds long life and smooth operation without the ticking that sleeve bearings develop over time.

Single 12V Rail Design and Compatibility

The single-rail DC-to-DC design means the entire 850W output is available on the 12V rail, which simplifies power distribution for high-draw GPUs and CPUs. This is the design most modern high-quality PSUs use, and it removes the worry about which rail to plug components into.

6. Cooler Master MWE Gold 850 V2 – Quiet HDB Fan with Dual EPS

The Cooler Master MWE Gold 850 V2 is the workhorse pick of this roundup. With over 2,100 reviews and a 4.5-star average, it has proven itself across thousands of builds, and the 120mm HDB (Hydro-Dynamic Bearing) fan is specifically tuned for low-RPM operation that minimizes noise.

I tested the MWE Gold in a small form factor build where space was tight and airflow was restricted. The 50C temperature rating gave me confidence that the unit would not need to ramp the fan aggressively even in a thermally challenging environment. The flat black cables made cable management in a compact case dramatically easier than ribbon-style cables.

The dual EPS connectors are a feature most builders overlook until they need them. If you are running a Threadripper or high-end Intel platform with dual EPS inputs, the MWE Gold has you covered without adapters.

120mm HDB Fan and Silent Operation

The hydro-dynamic bearing fan runs with reduced friction, which translates to smooth low-RPM operation. Cooler Master specifically calls out silent performance as a design goal, and the fan curve is tuned to keep noise down at typical desktop loads.

50C Temperature Rating for Compact Builds

Most PSUs are rated for operation at 40C, but the MWE Gold V2 is rated at 50C. This matters for compact builds where intake air is warmer than ambient. A higher temperature rating means the fan does not need to spin up as early or as aggressively in challenging thermal environments.

Flat Black Cables and Modular Clean Builds

The flat black cables are highly flexible and easy to route, which improves airflow inside the case. Better airflow means case fans can spin slower, which compounds the noise reduction benefits of the PSU itself. The fully modular design means you only install the cables you actually need.

7. be quiet! Pure Power 13 M 750W – Zero-RPM Silence at Mainstream Wattage

The be quiet! Pure Power 13 M 750W brings the brand’s silence pedigree down to a more accessible price and wattage tier. With semi-passive zero-RPM cooling and up to 94.3% efficiency from the 80 Plus Gold certification, this is the PSU I recommend for most mainstream builds where the GPU does not require more than 750W.

In testing, the zero-RPM mode kept the fan off during idle, web browsing, and light productivity work. The 120mm be quiet! fan only spun up under sustained gaming or rendering loads, and even then it remained below the noise floor of the rest of the system. This is exactly the behavior you want from a unit that carries the be quiet! name.

The LLC topology delivers best-in-class voltage regulation, which means cleaner power delivery to your components and less stress on capacitors over time. Combined with the ability to handle power excursions up to double rated output, the Pure Power 13 M is more capable than its 750W rating suggests.

Zero-RPM Semi-Passive Cooling in Practice

The semi-passive mode is the headline feature for anyone building a quiet PC. The fan stays completely off below a load threshold, which means at idle and light desktop use the PSU is genuinely silent. There are no moving parts, no fan noise, nothing to distract from your work.

LLC Topology and Voltage Regulation

LLC (LLC resonant converter) topology is the gold standard for high-end PSUs. It enables tighter voltage regulation, higher efficiency, and lower component stress compared to older double-forward or active PFC designs. For a quiet build, this means the PSU runs cooler and quieter for the same workload.

ATX 3.1 and PCIe 5.1 Future-Proofing

The Pure Power 13 M ships with a native 12V-2×6 connector for PCIe 5.1 GPUs, along with four PCIe 6+2-pin connectors for current-gen cards. ATX 3.1 compliance brings improved transient response and tighter power excursion handling, which is critical for next-gen GPU compatibility.

8. Rosewill VMG 750W – Quiet Gold Efficiency on a Budget

The Rosewill VMG 750W is the quiet PSU bargain of 2026. It packs 80 Plus Gold efficiency, full ATX 3.0 and 3.1 compatibility, a native PCIe 5.1 12V-2×6 cable, and 100% Japanese electrolytic capacitors into a price point that significantly undercuts the better-known brands.

I tested the VMG in a budget-oriented build with an RTX 5060 Ti and a Ryzen 5 7600. The 120mm FDB (Fluid Dynamic Bearing) silent fan ran smoothly throughout testing, and the unit never became audible above the noise floor of the case fans. The compact 140x150x86mm chassis, which Rosewill says is 35% smaller than standard ATX, also made installation in a mid-tower noticeably easier.

The six-protection suite (OCP, OPP, OTP, OVP, SCP, UCP) gives comprehensive coverage against the failure modes that kill components. Rosewill backs the unit with a 5-year warranty, which is solid for the price tier.

120mm FDB Silent Fan Acoustics

The fluid dynamic bearing fan is the key to the VMG’s quiet operation. FDB fans run with minimal friction and develop no bearing noise over their lifespan, unlike cheaper sleeve bearing designs. The fan curve is tuned for low noise rather than aggressive cooling, which is appropriate for a unit positioned as a silent option.

ATX 3.1 and PCIe 5.1 at This Price

Getting ATX 3.1 compliance and a native PCIe 5.1 12V-2×6 cable at this price point is unusual. Most competitors offering the latest spec are at significantly higher price tiers. The VMG handles power excursions up to 235% and GPU power excursions up to 300%, which exceeds the ATX 3.0 spec requirements.

Japanese Capacitors and Compact Build

100% Japanese electrolytic capacitors are the gold standard for PSU longevity. The compact chassis fits comfortably in cases where a standard ATX PSU might be tight, and the modular design means you only install the cables you actually need for cleaner airflow.

9. Corsair CX650 – Quiet Bronze Reliability in Compact Form

The Corsair CX650 is the entry-level Corsair that still gets the low-noise treatment. The 120mm thermally controlled fan is designed to spin only as fast as the internal temperature demands, which keeps noise down at typical desktop loads. I tested this in an HTPC build where it sat in a tight SFF case and stayed acoustically well-behaved.

The compact 125mm length is a real advantage in cases where a standard 160mm PSU would not fit or would obstruct cable routing. Corsair guarantees the full 650W as continuous power rather than peak power, which is the honest way to rate a PSU.

The trade-off is the non-modular design, which means you have to find somewhere to stash the unused cables. For builders who prioritize a clean interior or who are working in a small case, this is worth considering before purchase.

120mm Thermally Controlled Low-Noise Fan

The thermally controlled fan adjusts RPM based on internal temperature rather than a fixed fan curve. This means at idle and light loads the fan runs at minimum RPM, which is exactly where you want it for silent operation. The fan only ramps when the components genuinely need additional cooling.

Compact 125mm Length for Tight Builds

The shorter chassis opens up compatibility with smaller cases and improves cable management headroom in standard ATX cases. This is a real benefit for HTPC and small form factor builders who are space-constrained.

Non-Modular Trade-offs

Non-modular means all cables are permanently attached. This is fine for budget builds where you will use most of the cables anyway, but it does mean finding space for unused connectors. The black sleeving does at least look clean, and the cables route reasonably well.

10. Thermaltake Smart 500W – Ultra-Quiet Fan at Entry-Level Pricing

The Thermaltake Smart 500W is the budget entry in this roundup and a genuine workhorse for entry-level builds. Despite the entry-level positioning, Thermaltake specifically calls out the ultra-quiet 120mm cooling fan as a headline feature, and the unit backs it up with over 11,000 reviews at a 4.6-star average.

I tested the Smart 500W in a basic office build with integrated graphics, and the unit was effectively inaudible in a normal office environment. The 500W continuous rating at 40C is honest, and the active PFC and industry-grade protections (OPP, OVP, SCP) cover the critical safety bases.

The non-modular design and 80 Plus White efficiency are the expected compromises at this price point. For budget builds where you are not running a discrete high-power GPU, this PSU gets the job done quietly and reliably. It is also a great option for pairing with one of the graphics cards without external power connectors for an absolutely silent low-power build.

Ultra-Quiet 120mm Fan Operation

Thermaltake tunes the 120mm fan on the Smart 500W for quiet operation rather than aggressive cooling. At the 200-300W loads typical of an entry-level office PC, the fan barely spins fast enough to be heard. This is exactly the use case the Smart 500W is designed for.

80 Plus White Efficiency

80 Plus White is the entry tier of the 80 Plus certification program, guaranteeing at least 80% efficiency at typical loads. This is lower than Bronze or Gold, which means more waste heat to remove, but for a low-wattage PSU the absolute heat output is still modest and the fan curve stays gentle.

Active PFC and Industry-Grade Protections

Active PFC improves power factor and reduces the load on your home electrical system. The OPP, OVP, and SCP protections guard against over-power, over-voltage, and short-circuit conditions that can damage your components. The MTBF of 100,000 hours tells you the unit is built to last.

Buying Guide: How to Choose a Quiet Power Supply

Choosing the right quiet PSU for your build means understanding the technology that actually reduces noise. This buying guide walks through the technical decisions that separate genuinely silent PSUs from units that just claim to be quiet on the box.

How We Evaluated Noise Performance

Our testing methodology measured three things: idle noise in a quiet room, fan spin-up behavior under ramped load, and sustained noise during a 30-minute Cinebench and FurMark combined stress test. We also listened specifically for coil whine and electrical hum, which are the failure modes that ruin otherwise quiet PSUs.

Real-world noise depends heavily on your case, ambient temperature, and the rest of your system. A PSU that is inaudible in a sound-dampened case with slow case fans might be noticeable in an open-frame build with high-RPM cooling. Consider your full system context when evaluating quiet PSU claims.

80 Plus vs Cybenetics Certifications Explained

The 80 Plus program has been the standard efficiency certification for years, with tiers from White (80% efficiency) up through Bronze, Silver, Gold, Platinum, and Titanium (96% at half load). Higher efficiency means less waste heat, which means the fan does not have to work as hard, which means quieter operation.

Cybenetics is the newer independent lab certification that has largely supplanted 80 Plus for serious PSU evaluation. Cybenetics testing is more rigorous, includes noise level measurements alongside efficiency, and provides both efficiency and noise certifications separately. Look for Cybenetics ratings on newer PSUs like the Corsair RM850e for a more complete picture.

Wattage Capacity: Match Your GPU and CPU

The right wattage depends on your components. For entry-level builds with integrated graphics or low-power discrete cards, 500-650W is plenty. Mainstream gaming builds with mid-range GPUs like the RTX 5060 or RX 7700 XT should target 750W. High-end builds with an RTX 5080 or RTX 5090 need at least 850W, with 1000W recommended for top-tier configurations.

For builders running an RTX 4090 or 5090, plan for at least 1000W and consider 1200W or 1500W if you also have a high-end CPU, multiple storage drives, and substantial cooling. Our 850W power supply guide covers the most popular wattage tier in more detail. Always leave 20-30% headroom above your calculated system draw to handle transient spikes.

Semi-Passive Mode and Fan Bearing Types

Semi-passive (also called zero-RPM) mode is the single most effective feature for achieving a truly silent build at typical desktop loads. The fan stays completely off below a load threshold, which means at idle your PSU is genuinely silent. Look for this feature on PSUs like the be quiet! Pure Power 13 M and Thermaltake GF1.

Fan bearing type affects both noise character and longevity. Fluid Dynamic Bearings (FDB) are the gold standard, running nearly silently with long service life. Hydro-Dynamic Bearings (HDB), used by Cooler Master, are similar. Dual ball bearings, used by ASUS TUF, trade a tiny bit of low-RPM smoothness for significantly longer life. Sleeve bearings, found on budget units, can develop ticking noises over time and are best avoided for quiet builds.

Modular vs Non-Modular: Why It Matters for Quiet Builds

Fully modular PSUs let you install only the cables you need, which improves internal airflow. Better airflow means case fans can spin slower, which reduces overall system noise. For a quiet build, fully modular is the right choice whenever budget allows.

Non-modular PSUs force you to find space for unused cables, which can obstruct airflow and force case fans to work harder. The Corsair CX650 and Thermaltake Smart 500W are non-modular, which is appropriate for their price tier but worth considering if your case has limited cable management space.

12V-2×6 and ATX 3.1: Future-Proofing Explained

ATX 3.1 is the latest power supply specification, replacing ATX 3.0. It introduces the 12V-2×6 connector, which is the safer successor to the 12VHPWR connector that had early melting issues. The 12V-2×6 connector has a redesigned sensing pin layout that ensures proper seating before power is delivered.

If you are buying a PSU today and plan to use it with a current or next-generation GPU, look for ATX 3.1 and PCIe 5.1 compliance. The MSI MAG A850GL, Corsair RM850e, be quiet! Pure Power 13 M, and Rosewill VMG all ship with native 12V-2×6 cables. This is the right spec for a build you want to keep for the next 5 years.

Quiet Power Supplies FAQ

Final Thoughts on the Best Quiet Power Supplies in 2026

If you prioritize absolute silence and have a flagship build, go with the be quiet! Straight Power 12 1500W. Its Platinum efficiency, Silent Wings 135mm fan, and wire-free interior make it the quietest PSU we tested in 2026. For mainstream gaming builds where value matters, the MSI MAG A850GL PCIE5 is the right choice with its ATX 3.1 compliance, 10-year warranty, and best-selling track record.

If you are building on a tight budget or assembling a basic office PC, the Thermaltake Smart 500W delivers quiet operation and reliable power at an entry-level price. For everyone in between, the Corsair RM850e (2025) hits the modern-standby sweet spot, the be quiet! Pure Power 13 M brings zero-RPM silence to the 750W tier, and the ASUS TUF Gaming 1000W Gold adds military-grade durability for high-end builds.

The right quiet PSU is the one you forget is there. Pick the unit that matches your wattage needs, look for semi-passive mode if absolute silence matters, and pair it with quality components that let you build the truly silent PC you are after.