Cooling & Thermal Management

Why Cooling Matters

Modern CPUs and GPUs can generate 65߀“300+ watts of heat. Without adequate cooling:

• Thermal throttling: the CPU/GPU reduces its clock speed to lower heat output ߀” performance drops
• Thermal shutdown: the system powers off to prevent hardware damage
• Long-term degradation: sustained high temperatures shorten component lifespan

Thermal Design Power (TDP)

TDP is the maximum heat a cooling solution must dissipate under sustained load. A CPU rated at 125 W TDP needs a cooler rated for at least 125 W.

ß? ?? Modern Intel Core K-series and AMD Ryzen X-series CPUs can exceed their rated TDP under boost. Choose a cooler rated 30߀“50% above the CPU TDP for headroom.

Thermal Paste

Thermal paste (also called thermal compound or TIM) fills the microscopic gaps between the CPU heat spreader and the cooler base, dramatically improving heat transfer.

Application methods:

Method	Best for
Pea (centre dot)	Most CPUs ߀” spreads under pressure
Cross/X pattern	Large IHS like Intel Core i9 / Threadripper
Thin spread	Pre-applied by some coolers

• Use a pea-sized amount ߀” more is not better; excess paste insulates rather than conducts
• Clean old paste with isopropyl alcohol (90%+) and a lint-free cloth before reapplying
• Re-apply every 3߀“5 years or if temperatures rise significantly

Air Cooling

Air coolers use a metal heatsink with heat pipes to spread heat, and a fan to move air through the fins.

Types:

• Top-down (tower with single fan): Good for low-profile builds; blows cool air directly onto the VRMs
• Twin-tower (dual fan): Best air cooling performance; large footprint
• Low-profile: For compact/HTPC cases; limited cooling capacity

Popular options: Noctua NH-D15, be quiet! Dark Rock Pro, DeepCool AK620

Liquid Cooling (AIO)

An All-In-One (AIO) liquid cooler uses a pump, tubes, radiator, and fans. The pump circulates coolant between a block on the CPU and the radiator.

Radiator Size	Fan Count	Suitable for
120 mm	1G— 120 mm fan	Budget; low TDP CPUs
240 mm	2G— 120 mm fans	Mainstream; up to ~200 W
280 mm	2G— 140 mm fans	High-performance
360 mm	3G— 120 mm fans	Enthusiast; high TDP CPUs

AIO advantages: Better performance than most air coolers, looks clean, no RAM clearance issues AIO disadvantages: Moving parts (pump) can fail, typically noisier at low loads, more expensive

Custom Water Cooling (Custom Loop)

Custom loops use separate components: reservoir, pump, waterblock(s), radiator(s), tubing, fittings. Maximum performance and customisability ߀” complex to build and maintain.

Case Airflow

Good airflow moves cool air in through intake fans and exhausts hot air out.

Recommended layout:
  Front/Bottom: INTAKE fans (cool air in)
  Rear/Top:     EXHAUST fans (hot air out)

Positive pressure: more intake CFM than exhaust ߀” slight pressure inside, less dust ingress Negative pressure: more exhaust than intake ߀” slightly cooler but more dust builds up

Always ensure intake fans have dust filters. Clean them every 3߀“6 months.

GPU Cooling

GPUs use their own coolers (reference blower or aftermarket triple-fan). Key points:

• Leave at least one PCIe slot gap above the GPU if possible ߀” improves airflow
• Aftermarket GPU coolers (e.g. Arctic Accelero) can dramatically reduce GPU temperatures on reference designs
• Undervolting the GPU reduces heat with minimal performance loss ߀” use MSI Afterburner

Monitoring Temperatures

Tool	What it monitors
HWiNFO64	CPU, GPU, VRM, NVMe, system temps
Core Temp	CPU per-core temperatures
GPU-Z	GPU temperature, VRAM temperature
BIOS	Fan curves, temperature thresholds

Healthy idle temperatures (desktop):

• CPU: 30߀“50 ?°C
• GPU: 35߀“55 ?°C
• NVMe SSD: 40߀“60 ?°C