The ACX cooled video cards exhausts their hot air straight into the computer case rather than out the back, outside the case, like the Reference cooled cards do. If you have a very small form-factor case like the Asus G20AJ has, with its limited airflow, then its best to get a Reference card, and preferably the non-overclocked model, since they require more power, which is limited w/the G20AJ.
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. ROG Zephyrus GA401QM (Q14) Laptop, AMD Ryzen 9 5900H CPU; Nvidia RTX 3060 GPU; 24 GB DDR4 (1x8 GB, 1x16); 1 TB Samsung Pro980 M.2 SSD; Windows 10 Pro