Wiktionary
power wall
n. 1 (context marketing English) In retail selling, a large, visually appealing display of products intended to attract the interest of customers. 2 (context marketing Canada English) Behind retail sales counters in jurisdictions where tobacco advertising has been banned or heavily restricted, a prominent, enticing display of tobacco products. 3 (context computing English) The rapidly increasing loss of efficiency due to overheating as the power/speed of a CPU increases.