Your PC’s been running hot. The CPU hits 95C in BIOS, the GPU thermal throttles 20 minutes into a game, and the case feels like a space heater. Heat isn’t just uncomfortable – it forces silicon to clock down, shortens component lifespan, and crashes systems mid-session. Most overheating has nothing to do with a defective part. It’s dust, dried paste, bad airflow, or a fan curve that lets components cook before ramping. Here’s how to find and fix each cause.
First check the obvious
Download HWiNFO64 and run it in sensors-only mode. Watch CPU package temp, GPU edge temp, and motherboard VRM temp at idle and under load. Idle CPU should sit at 35-45C. Idle GPU should be 30-40C. Anything above that with no workload means airflow or paste is shot. Under a 10-minute game session, CPU should stay below 85C and GPU below 80C. Hitting 90C+ means thermal throttling has already started.
Second, open the side panel and look at fan filters. If they’re caked with grey fluff, that’s your problem. Third, confirm fans are actually spinning. A dead CPU cooler fan will spike temps to 100C in seconds. A dead exhaust fan creates a hotbox effect where every other fan recirculates warm air. You’ll feel it – the case top will be noticeably hot to touch within 5 minutes of boot.
Cause 1: Dust buildup
Dust is the number one overheating cause on PCs older than 18 months. It coats heatsink fins, blocks fan filters, and forms an insulating blanket on the GPU shroud. A heatsink with 2 mm of dust between fins loses 30-40% of its dissipation capacity. The CPU runs 10-15C hotter at the same load.
Diagnostic: pop the side panel and look at the CPU heatsink fins between the tower and the rear exhaust fan. If you can’t see daylight through the fins, they’re packed. Fix: power off, unplug, take the PC outside or to a garage, and blow it out with compressed air. Hold fans still with a finger while spraying so they don’t spin past their bearing rating. Hit the CPU cooler, GPU shroud, PSU intake (briefly), and every case fan. Wipe down filters with a damp microfiber after. Do this every 6 months minimum, every 3 months if you’ve got pets.
Pros
- Dual Molex and 3-pin connectors cover both older PSU-direct and modern motherboard-header setups.
- 24.7 dBA noise floor keeps the fan audibly quiet at its fixed 1350 RPM operating speed.
- Standard 120x120x25mm frame drops into virtually any case with a 120mm mount point.
- 30,000-hour rated lifespan is typical for this category and acceptable for non-critical cooling roles.
Cons
- 3-pin connection provides no PWM speed control; fan runs at fixed 1350 RPM regardless of thermal load.
- No published static pressure spec, making intake performance through dust filters or dense radiators unverifiable from source data.
The Apevia AF212S-BK is a budget-tier 120mm case fan sold in a 2-pack, targeting builders who need basic airflow coverage without spending heavily per fan. At 120x120x25mm, it fits standard mounts in mid-tower and full-tower cases. The primary audience is first-time builders or anyone replacing failed stock fans in an existing system.
The most defining feature here is the dual-connector approach: each fan ships with both a 4-pin Molex plug and a 3-pin motherboard header cable. This makes it functional in older systems without fan headers and in modern builds where header count matters. Airflow is rated at 57.67 CFM at 1350 RPM, which is adequate for general intake or exhaust duties in cases with reasonable panel ventilation.
The fixed 1350 RPM speed is a real trade-off. Because the 3-pin connection lacks PWM control, the fan cannot slow down during light loads or spin up under thermal stress. Noise at 24.7 dBA is acceptable at this speed, but buyers expecting dynamic speed control from a motherboard will not get it. Static pressure data is absent from source specs, so performance through restrictive filters or radiators is unconfirmed.
Buy this if you need inexpensive, no-frills airflow coverage in a budget build or want a quick replacement for a dead case fan. Skip this if your build requires PWM-controlled fans for quiet idle profiles or if you need verified static pressure figures for push-pull radiator configurations.
Fan Dimensions and Mounting: Each unit measures 120x120x25mm, fitting any standard 120mm case mount. The frame accepts four standard M3 fan screws. Two fans are included per pack, covering a single intake-plus-exhaust pairing in a typical budget case layout.
Airflow and Noise: Rated airflow is 57.67 CFM at a fixed 1350 RPM, with a tolerance of plus or minus 10 percent on speed. Noise level is specified at 24.7 dBA. No static pressure rating is published in the source data, so pressure-sensitive applications such as radiator mounting cannot be evaluated from listed specs alone.
Connector Types: Each fan includes a 4-pin Molex connector for direct PSU connection and a 3-pin motherboard header cable. The 3-pin connection supports tachometer feedback for RPM monitoring but does not support PWM speed control. Fan speed is fixed at 1350 RPM regardless of header signal.
Rated Lifespan: The fan is rated for 30,000 hours of continuous operation. At 24 hours per day, that corresponds to roughly 3.4 years of uninterrupted use, which is typical for fans at this price tier and suitable for non-critical secondary airflow roles.
Cause 2: Dried-out thermal paste
Thermal paste dries out and loses conductivity after 3-5 years. On laptops, sooner – thermal cycling hammers the compound. Symptoms: CPU temps creep up 5-10C every six months, you start hitting 95C in workloads that used to top out at 80C, and the cooler itself stays cool to the touch because heat isn’t transferring.
Fix: repaste. Pull the cooler, clean both the CPU IHS and cooler base with 99% isopropyl alcohol and a microfiber, then apply a pea-sized dot of Arctic MX-4 or MX-6 to the center of the IHS. The cooler pressure spreads it. Don’t use the X-pattern or buttering method on Ryzen – it traps air. Mount the cooler back evenly, tightening screws in a star pattern. Run a load check with Cinebench R23 for 10 minutes and watch temps. You should see a 10-20C drop on a system that was overdue.
Pros
- Non-conductive at 3.8 x 10 to the 13 ohm-cm, so accidental overspread poses minimal short circuit risk.
- Operational range of -50 to 150 degrees Celsius covers every consumer CPU and GPU thermal scenario.
- 31,600 Poise viscosity is workable without being runny, lowering risk of air pockets during application.
- Metal-free carbon formula avoids corrosion risk on aluminum cooler contact surfaces, unlike liquid-metal compounds.
Cons
- Zero owner reviews at time of writing, so real-world thermal delta versus Kryonaut or NT-H1 is unverified.
- Thermal conductivity value is not stated in source data, making direct spec comparison with competitors impossible.
ARCTIC MX-4 is a carbon microparticle thermal compound targeting CPU and GPU applications in consumer PC builds. It sits in the non-conductive, metal-free category alongside NT-H1 and Kryonaut. At 4g it covers multiple applications. It suits first-time builders, budget system integrators, and anyone reapplying compound after a cooler swap.
The defining technical feature is non-conductivity confirmed by a volume resistivity of 3.8 x 10 to the 13 ohm-cm. That figure puts overspread risk firmly in safe territory for exposed CPU and GPU pads. Viscosity at 31,600 Poise is thicker than many competitors, which aids controlled application but may require slightly more spreading pressure on larger IHS surfaces.
No thermal conductivity value is published in the source data, which is a genuine gap. Without a rated conductivity figure in watts per meter-kelvin, direct benchmarking against Thermal Grizzly Kryonaut at 12.5 W/mK or NT-H1 at 8.9 W/mK is not possible from spec sheets alone. ARCTIC claims 8 years durability, but with zero owner reviews at time of writing that figure cannot be independently corroborated.
Buy this if you need a non-conductive compound for a stock-speed CPU or mid-range GPU build and want a low-risk first application. Skip this if you are delidding, pushing high TDP CPUs such as a Ryzen 9 9950X or Core i9-14900K under sustained all-core load, and need verified conductivity numbers to make a compound choice.
Electrical Safety: Volume resistivity measures 3.8 x 10 to the 13 ohm-cm, classifying MX-4 as non-conductive and non-capacitive. For comparison, silver-based pastes typically fall below 10 to the 6 ohm-cm, making this formula meaningfully safer for DIY application near exposed pads.
Thermal Operating Range: Continuous use is rated from -50 to 150 degrees Celsius. Consumer CPUs such as AM5 Ryzen and LGA1700 Intel parts typically throttle before 100 degrees Celsius junction, so the 150-degree ceiling provides adequate headroom without concern.
Consistency and Application: Viscosity is rated at 31,600 Poise and density at 2.50 g/cm cubed. This combination produces a paste that holds position on vertical IHS surfaces during cooler mounting, reducing the likelihood of pump-out under thermal cycling.
Durability Claim: ARCTIC rates MX-4 for at least 8 years of continuous use without reapplication. Thermal conductivity in watts per meter-kelvin is not specified in the source data and should be confirmed via independent review before selecting this paste for high-TDP applications above 200W.
Cause 3: Bad case airflow
Even with clean fans and fresh paste, a case set up wrong will cook the whole system. The rule: more intake than exhaust, mounted low front and high rear. Two 140mm intakes at the front plus one 120mm exhaust at the rear is the classic positive-pressure layout. Reverse those fans accidentally (it’s easy to do on AIO push-pull mounts) and you’re pulling hot exhaust back through the radiator.
Check fan direction by looking at the arrow on the fan frame, or feeling for airflow with your hand at idle. Cables routed across the front intake area choke airflow more than people realize. Tuck them behind the motherboard tray. If your GPU sags and blocks the bottom intake fan, install a support bracket. AIO radiators belong in the top with fans as exhaust, or the front with fans as intake – not the bottom, where the pump will draw air over time and gurgle.
Pros
- No-spread application reduces installation error rate, especially useful for inexperienced builders or cramped GPU die layouts.
- Non-conductive and non-capacitive formula eliminates short-circuit risk on CPU and GPU contact surfaces.
- High cohesion resists pump-out through repeated heat cycles, maintaining bond line integrity over extended use periods.
- 8g syringe volume covers multiple CPU and GPU applications, practical for system builders handling several installations.
Cons
- Thermal conductivity value is not specified in product data, making direct benchmark comparison against Kryonaut or MX-6 impossible.
- Cannot be manually spread by design, which may frustrate users accustomed to traditional application methods on large IHS surfaces.
ARCTIC MX-7 is a high-viscosity, non-metallic thermal compound designed for CPU, GPU, laptop, and console applications. It sits in the high-performance non-conductive paste tier, targeting PC builders, system integrators, and enthusiasts who want a low-maintenance compound that holds up through multiple thermal cycles without reapplication.
The defining feature here is the press-and-mount application method. MX-7 is intentionally too viscous to spread manually. Under cooler mounting pressure, it flows outward from the application point and forms a thin, consistent bond line. Based on owner reports, this approach reliably eliminates the air pocket failures that plague thin or uneven manual spreads, particularly on small CPU dies like AMD Ryzen and Intel Core architectures.
The honest trade-off is the absence of a published thermal conductivity figure in available product data. Buyers who need a verified W/mK rating for engineering decisions or thermal modeling cannot confirm this compound against competitors on spec alone. The no-spread design also constrains users who prefer tile or cross application methods for large GPU heat spreaders or older CPU IHS designs.
Buy this if you want a fire-and-forget thermal compound for a new CPU or GPU build where reapplication frequency matters more than chasing marginal conductivity differences. Skip this if you need a documented thermal conductivity value for a controlled cooling experiment or overclocking validation build where compound selection is part of a benchmarked variable.
Application Method: MX-7 uses a pressure-distribution method only. Manual spreading is not supported by design. The high-viscosity formulation requires standard cooler mounting pressure to achieve the target bond line, which eliminates a common installation variable across LGA1700, AM5, AM4, and mobile socket installations.
Electrical Safety: Confirmed electrically non-conductive and non-capacitive. This makes the compound safe for application on CPU and GPU contact surfaces where overflow onto surrounding circuitry or SMD components carries risk. No secondary insulation step is required for standard cooler installations.
Longevity and Stability: Formulated with high internal cohesion to resist pump-out, dry-out, and bleeding. This is relevant for systems that see frequent power cycling or sustained high-TDP loads, where lower-cohesion compounds can migrate away from the die contact area over 12 to 18 months of operation.
Package Contents: 8g syringe. At a typical CPU application volume of 0.5g to 1g per installation, the 8g size covers approximately 8 to 16 CPU applications, making it practical for builders working across multiple systems or stocking a small parts inventory.
Cause 4: Fan curves set too lazy
Stock fan curves from motherboard makers prioritize silence over cooling. The CPU fan often won’t ramp until 70C, and by then you’ve already spent 10 seconds at peak temp. Same with GPU – many cards idle with fans off until 55-60C, which is fine, but the ramp from 60 to 80C is often too gentle.
Fix: enter BIOS, find Q-Fan Control or Smart Fan, and rebuild the CPU curve. At 40C set fans to 40%. At 60C set them to 70%. At 75C set 100%. The PC will be louder but temps drop noticeably. For GPU, use MSI Afterburner’s fan curve editor. Set fans to start ramping at 50C and hit 100% at 80C. Hysteresis matters too – set a 5C deadband so fans don’t oscillate every few seconds during light loads.
When to upgrade or replace
If the stock Intel or AMD cooler ships with your CPU and you’re running a Ryzen 7 7700X or Core i7-14700K, that cooler isn’t enough. Period. Those chips dump 105-180 W under load and need a dual-tower air cooler like the Peerless Assassin 120 or a 280mm+ AIO. The wraith Stealth or Laminar RM1 will hit 95C in seconds and never come down.
Cases over 6 years old often have airflow holes drilled too small or fan mounts in awkward spots. If you’ve cleaned, repasted, and tuned curves but still throttle, the chassis is the bottleneck. Modern mesh-front cases (Lancool 216, NR200P V2, Pop Air) cool 8-12C better than older “silent” cases with restrictive front panels. GPUs sagging from their own weight stress the PCIe slot and can lose contact – a $10 support bracket fixes that.
Common questions
What temperature is dangerous for a CPU?
Modern Ryzen 7000 and Intel 13th/14th gen chips are designed to boost until they hit 95C. That’s not damage, it’s the chip running at spec. The danger zone starts above 100C, where thermal throttling kicks in hard and you’ll see clock drops. Sustained 100C+ over months degrades silicon, but a few minutes won’t kill the chip.
Is liquid cooling worth it?
For Ryzen 9 and Core i9 chips, yes. A 280mm or 360mm AIO handles 200+ W where air coolers tap out around 250 W under sustained load. For Ryzen 5/7 and Core i5/i7, a good dual-tower air cooler matches AIO performance for half the price and won’t leak in three years.
Why is my GPU hotter than my CPU?
GPUs are designed to run hotter. An RTX 4070 happily sits at 75C under load – that’s normal. The number to watch isn’t edge temp, it’s hot spot or junction temp. Anything above 95C hot spot signals dried paste or pump failure on the card. AMD cards report this in their drivers; NVIDIA cards need HWiNFO64.
Can a bad PSU cause overheating?
Indirectly, yes. A failing PSU can’t deliver clean voltage, so VRMs on the motherboard and GPU work harder to compensate. VRM temps climb, and if they hit 110C+ the board throttles the whole system. If you’ve ruled out the cooler, paste, and airflow and still see weird thermal behavior, check PSU age and brand. Anything over 7 years or sub-$60 generic should go.
