Why aren't we cooling the back of our CPU?

In this Linus Tech Tips video, the team explores an unconventional idea: cooling a CPU from the back of the motherboard. The opening segment frames the question by showing heat on the backside of the motherboard and asking whether removing that heat via a backplate cooler could meaningfully improve overall CPU temperatures. Early tests with a simple fan behind the motherboard yield only a tiny temperature shift, suggesting that backing a cooler against the back is not a straightforward win. The creators then describe the practical challenges: contacting a cooler to the back of the motherboard is impeded by the CPU back plate, traces on the motherboard, and the nonflat nature of back-side components. They conclude that any potential gains depend on heat transfer through the motherboard itself, not just the back side, and they set out to build a custom back plate to evaluate true contact and cooling efficiency. The middle section documents the design process, including removing the back plate, fabricating a new metal back plate, and using a thicker cushioning layer to achieve contact despite nonflat surfaces. The tests compare front versus back mounting in multiple environments, including a controlled environmental chamber and a normal office setting, to reveal how real-world airflow and room temperature affect outcomes. The final results show that while back cooling can produce small improvements in certain conditions, the gains are minimal compared to a conventional front-mounted cooler, and front cooling generally remains the more effective solution. The video closes with a practical takeaway: back cooling is possible but not a universal fix, and the most impactful approach is to optimize front-side cooling or pursue other methods only if the goal is marginal improvement rather than a dramatic performance boost. The host encourages audience interaction, invites feedback on what could be tested next, and plugs sponsored content while underscoring the value of empirical testing in understanding cooling performance.

Topics · science and technology · engineering · computer hardware · thermodynamics · experimental testing · technology review