Loop Planning, Tube Routing and Order

Planning the Loop: CPU to GPU to Radiator to Pump/Reservoir

The most important principle to follow when routing tubing in a water cooling loop is to ensure that coolant flows through all components in a continuous cycle. While the order of components like the CPU block, GPU block, radiator, pump, and reservoir can vary, the overall effectiveness of cooling does not depend heavily on which comes first or last in the loop.

1. Start with the Reservoir and Pump: It's a good practice to have the reservoir directly feeding into the pump. This ensures that the pump never runs dry, which is crucial for its longevity and the efficiency of the cooling loop. The reservoir should be positioned slightly higher than the pump to allow gravity to help feed coolant into the pump.
2. CPU Block: From the pump, route the tubing to the CPU water block. The CPU is usually the hottest component in most systems, so cooling it early in the loop makes sense from a thermal perspective. The tubing should be routed in a way that minimizes sharp bends to avoid restricting coolant flow.
3. GPU Block: After the CPU, route the tubing to the GPU water block. The GPU tends to be the second-highest heat-generating component in a PC, so cooling it next ensures that both key components are efficiently cooled.
4. Radiator: From the GPU block, the tubing should then go to the radiator. At this stage, the coolant will have absorbed the heat from both the CPU and GPU, and the radiator will dissipate that heat. You can mount the radiator at the top, front, or bottom of your case, depending on your case layout. Ensure that the tubing runs to and from the radiator in a way that avoids sharp angles or kinks.
5. Return to the Reservoir: After passing through the radiator, route the tubing back to the reservoir, completing the loop. This ensures that the cooled liquid is stored in the reservoir before being cycled back to the pump for another round.

Component Order: It Doesn’t Matter Which Way

A common question in water cooling is whether it matters which component is cooled first. The answer is that the specific order of the CPU, GPU, and radiator does not significantly impact the overall performance, as long as the loop is continuous and efficient. Once the coolant is circulating through the loop, it reaches thermal equilibrium, meaning the temperature of the coolant stabilizes as it flows continuously.

For example, whether you cool the CPU before the GPU or the GPU before the CPU will make only a small difference (if any) in overall temperatures. What matters most is that all components are connected in a single loop without excessive bends, tight angles, or restrictions that could impede flow. The water blocks are designed to work efficiently regardless of the flow direction, so the coolant can enter or exit from either port as long as it continues through the loop.

Additional Tips for Efficient Tubing Routing

• Minimize Bends and Length: Keep tubing as short and direct as possible. Longer tubing and sharp bends can lead to reduced flow rates and affect cooling efficiency.
• Use Angled Fittings if Needed: If you’re dealing with tight spaces or difficult routing angles, consider using 45° or 90° angled fittings to help guide tubing in a clean, efficient manner. This helps reduce the chance of kinks in the tubing.
• Keep the Loop Simple: Don’t overcomplicate the loop by adding unnecessary components or overly complex routing. A clean, simple loop is easier to maintain and generally performs better than a cluttered or convoluted one.

Ultimately, routing tubing in a custom water cooling loop is about creating a continuous, efficient cycle of coolant flow. The order in which components like the CPU, GPU, radiator, and reservoir are connected is less important than ensuring smooth, unrestricted flow and keeping the system leak-free. By keeping tubing runs short, avoiding sharp bends, and maintaining a continuous flow between the pump, water blocks, radiator, and reservoir, your water cooling loop will function optimally, keeping your system cool and stable.