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Radiator Intake vs Exhaust: How to Balance CPU and GPU Temperatures

Radiator intake usually produces lower CPU temperatures because the radiator receives cool room air. Radiator exhaust usually produces better GPU, motherboard, memory, and SSD temperatures because CPU heat leaves the chassis instead of being released inside it.

But it is not the complete answer, because radiator size, GPU power, case restriction, ambient temperature, fan pressure, dust filters, pump speed, workload type, and the location of every other fan can reverse an apparently obvious decision.

A 360 mm radiator mounted at the front as intake may make the CPU monitoring graph look excellent, yet the same configuration can feed noticeably warmer air into an open-shroud graphics card, raise GPU fan speed, increase hotspot temperature, and make the entire machine louder during gaming.

So which temperature are we actually trying to fix?

For most gaming PCs, my starting recommendation is simple: mount the CPU radiator at the top as exhaust, use front or side fans as intake, and preserve a separate supply of cool air for the graphics card. For CPU rendering, compiling, simulation, or other processor-heavy workloads, a front or side radiator configured as intake can be the better choice.

The hard truth is that there is no universally “best” radiator orientation. There is only the layout that handles your real heat load without making another component pay for the improvement.

The Practical Verdict: Intake Helps the CPU, Exhaust Helps the System

A radiator is a heat exchanger. It transfers energy from the CPU into the coolant, from the coolant into the radiator fins, and from those fins into the air passing through them.

Where that air goes determines who inherits the heat.

With an intake radiator, outside air passes through the radiator first. The CPU receives the lowest available air temperature, but the warmed radiator air then enters the chassis and travels toward the GPU, voltage-regulator modules, RAM, M.2 drives, and other components.

With an exhaust radiator, internal case air passes through the radiator and leaves the chassis. The CPU cooler receives warmer air, but the heat removed from the processor is discharged directly outside.

 reaches the same conclusion: front or side radiator intake generally favors CPU temperature, while a top radiator configured as exhaust generally favors GPU temperature. Noctua also advises pairing front radiator intake with top and rear exhaust so warmed radiator air does not remain trapped inside the case.

Radiator configurationCPU temperature tendencyGPU temperature tendencyInternal case temperatureBest use caseFront intakeUsually lowestMay increaseHigherCPU rendering, compiling, simulationSide intakeUsually lowDepends on GPU intake pathModerate to higherDual-chamber casesTop exhaustSlightly higherUsually lowerLowerGaming and mixed workloadsFront exhaustUsually higherCan improve if GPU has separate intakeLower near the frontUnusual layouts with bottom intakeTop intakeCan reduce CPU temperatureCan disrupt GPU exhaust flowHighly case-dependentCompact or specialized layoutsDual radiators, one intake and one exhaustBalancedBalanced with dedicated GPU intakeModerateHigh-power dual-loop systems

These are directional tendencies, not guaranteed temperature differences. Anyone promising that changing radiator direction will produce an exact 5°C improvement without knowing the case, fan speed, room temperature, GPU cooler, radiator thickness, and workload is selling certainty that does not exist.

Why Modern CPU and GPU Heat Loads Fight Each Other

In 2026, a high-end gaming system can generate a severe combined heat load. NVIDIA specifies that a GeForce RTX 5090 can draw up to 575 W, while Intel lists a 250 W Maximum Turbo Power figure for the Core Ultra 9 285K. That creates a theoretical CPU-and-GPU total of 825 W before the motherboard, pump, fans, memory, storage, and power-conversion losses are counted.

That changes the radiator intake vs exhaust debate.

In an older system with a 150 W graphics card, passing radiator-warmed air toward the GPU might have been a minor compromise. In a machine containing a 400 W or 575 W graphics card, the GPU may already be the largest sustained source of heat in the chassis.

And most modern gaming cards do not send all that heat through the rear I/O bracket. Open-air and flow-through coolers release a large portion of it back into the case, where top fans, rear fans, and the CPU radiator must deal with it.

This is why I treat gaming airflow as a GPU supply problem first and a CPU heat-removal problem second. The graphics card needs a dense, unobstructed stream of cool air near the lower half of the case. The CPU radiator needs enough airflow to remove heat without stealing that supply.

 expands on this conflict, including why fan count alone tells us almost nothing about whether the GPU is receiving usable airflow.

Airflow diagrams are neat. Real cases are not.

Graphics cards deflect air. Radiators restrict it. Filters load with dust. Tempered-glass panels force air through narrow side vents. Cables produce turbulence. A top-front fan can even redirect air before it reaches the component it was supposed to cool.

GamersNexus demonstrated this in its HAVN BF 360 Flow testing. The stock configuration averaged 40°C for GPU temperature in the reported test, while adding two 180 mm top fans as exhaust reduced that result to 39°C. A mixed top intake-and-exhaust arrangement raised the GPU average to 42°C, even though the top-front intake benefited CPU temperature. The test illustrates the real trade: helping the CPU airflow route can interfere with the GPU’s route.

That 3°C spread is not a universal prediction. It is evidence that fan direction can change airflow behavior in ways a simple “hot air rises” diagram will not capture.

Natural convection is weak compared with forced airflow from multiple 120 mm or 140 mm fans. Once case fans are running, fan pressure, component geometry, restrictions, and inlet location dominate the route.

PCWorld’s cooling guidance makes the practical choice clear: place the AIO radiator at the top as exhaust when GPU cooling is the priority, accepting a slightly warmer CPU in exchange for a cooler graphics card. 

That advice is especially relevant to gaming systems, where the GPU can remain heavily loaded for hours while CPU utilization changes from scene to scene.

A front intake radiator gives the CPU cooling loop access to room-temperature air before another component heats it. This is normally the strongest arrangement for reducing CPU package temperature or coolant temperature.

It also creates a predictable penalty: the air leaving the radiator is warmer than the air entering it.

That warmed air may travel directly into the graphics card. The impact depends on radiator heat output, coolant temperature, fan speed, case volume, GPU position, and whether another intake supplies cool air below or beside the card.

A front intake radiator is not automatically bad for gaming. But I would not install one in front of a high-power open-shroud GPU without testing GPU core temperature, hotspot temperature, fan RPM, and noise.

For a deeper examination of that exact trade-off, see ACEGEEK’s analysis of 

how front-mounted AIOs affect GPU thermals

A top exhaust radiator removes CPU heat directly from the case. It also helps collect rising and fan-driven exhaust from the graphics card, motherboard, memory, and surrounding components.

The penalty is obvious: the radiator receives air that has already been warmed inside the chassis.

CPU package and coolant temperatures may therefore increase compared with front intake. But the rest of the system often benefits because the radiator is no longer preheating the graphics card.

Corsair also notes that a top-mounted radiator can exhaust CPU heat instead of releasing it around the graphics card, SSD, and other internal hardware. 

My default gaming layout remains front intake, optional bottom intake, top radiator exhaust, and rear exhaust. It is not glamorous. It is simply difficult to break.

Does Radiator Intake Increase GPU Temperature?

Yes, radiator intake can increase GPU temperature because air heated by the CPU radiator enters the chassis before reaching the graphics card.

But the size of that increase cannot be predicted from radiator orientation alone.

A 240 mm radiator cooling a moderate processor may add very little heat to the case. A 360 mm radiator handling a processor near 250 W under an all-core workload can create a much warmer intake stream. A bottom intake placed directly below the GPU may cancel much of the penalty. A solid front panel may make the entire arrangement fail before radiator direction even matters.

This is where many online comparisons become misleading. They test CPU-only workloads, report that front intake won, and stop.

Of course it won. The graphics card was barely producing heat.

A useful radiator comparison must include at least three conditions:

The third test is the one I trust most. It exposes whether the CPU radiator and graphics card are competing for the same air, whether exhaust capacity is adequate, and whether a temperature improvement simply moved heat from one sensor to another.

You can choose the correct radiator position and still get poor results by using the wrong fan.

Radiator fins create resistance. Dust filters, mesh panels, restrictive grilles, and narrow glass-panel vents add more. A high open-air CFM rating does not guarantee strong airflow through those obstacles.

choosing radiator fans versus case-airflow fans

 explains why static pressure, measured in mmH₂O, matters when a fan must force air through radiator fins or dense filters.

The best radiator fan configuration is not necessarily the one with the highest advertised RPM or CFM. A noisy fan running at 2,000 RPM may win a short benchmark but lose in daily use when you reduce it to 900 RPM because the sound is unbearable.

We need usable cooling. Not a specification contest.

“Push” means the fan forces air into and through the radiator. “Pull” means the fan draws air through the radiator. Both can work.

Push is normally easier to clean because dust collects on the visible radiator face. Pull may simplify installation or improve appearance in certain cases. The performance difference is often smaller than the effect of fan quality, sealing, radiator restriction, and RPM.

Push-pull places fans on both sides of the radiator. It can help thick or restrictive radiators, but it doubles fan count, cable complexity, cost, and potential noise. I would not use push-pull on a mainstream 27 mm AIO radiator unless controlled testing showed a meaningful benefit.

Three intake fans do not automatically create positive pressure.

A filtered 360 mm intake radiator can move less actual air than two unrestricted exhaust fans. Radiator fins, dust filters, fan curves, panel openings, and fan models all affect real airflow.

Slight positive pressure means filtered intake airflow is somewhat greater than exhaust airflow. It usually helps limit dust entering through unfiltered gaps.

Negative pressure means exhaust airflow is stronger. It can remove heat aggressively, but it also draws air and dust through PCIe slots, panel seams, cable openings, and every other unfiltered gap.

For most radiator systems, I start near neutral or slightly positive. Then I use fan curves to make intake respond to GPU load and radiator fans respond to coolant or CPU temperature.

Do not tune pressure by fan count. Tune it by behavior.

Hold a thin strip of tissue near unfiltered openings. If air is consistently being pulled inward through every seam, the system is probably operating with negative pressure. That may be intentional, but it should not be an accident.

The Best AIO Radiator Airflow Setup by Workload

Use the radiator as top exhaust. Feed the graphics card with front, side, or bottom intake. Keep a rear exhaust fan behind the CPU socket area.

This arrangement sacrifices a small amount of CPU cooling efficiency to prevent the CPU radiator from warming the GPU intake path.

Use the front or side radiator as intake. Add strong top and rear exhaust. Confirm that the graphics card remains within acceptable temperature, clock, and noise limits.

This setup gives the radiator the coolest available air, which can improve sustained CPU behavior.

Start with top exhaust. Test front intake only when CPU temperature, coolant temperature, or fan noise remains unacceptable.

I would rather accept a slightly warmer modern CPU than feed a 400 W-plus GPU a constant stream of radiator-heated air.

Intel explains that its processors use internal thermal-control mechanisms near their model-specific Tjunction maximum, with maximum junction limits commonly falling between 100°C and 110°C across products. AMD similarly states that processor temperature depends on the cooler, system airflow, ambient temperature, settings, and workload—not on one isolated sensor reading. Always check the specification for the exact processor rather than treating one universal temperature as safe for everything.

Compact systems often use unconventional airflow routes because the radiator, GPU, PSU, and side panels sit close together. A side intake radiator may outperform top exhaust. A rear intake may be useful. Negative pressure may help evacuate a GPU heat pocket.

Use one radiator as intake and one as exhaust as the baseline. Preserve a separate intake for the GPU whenever possible.

In a conventional tower, front radiator intake plus top radiator exhaust is a logical starting layout. In a dual-chamber chassis, side radiator intake, top radiator exhaust, and bottom GPU intake can create cleaner thermal zones.

 covers radiator interaction, pressure balance, coolant temperature, and independent GPU intake in greater detail.

Case Layout Can Overrule Every General Recommendation

The case decides which options are physically realistic.

Radiator intake improves CPU cooling but can heat the GPU. Radiator exhaust protects case temperatures. Learn how to balance both with a tested airflow plan.

Avis

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Entrée vs sortie d'air du radiateur : comment équilibrer les températures du processeur et de la carte graphique

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