It was tried before, with professional ARM server hardware:<p><a href="http:&#x2F;&#x2F;www.anandtech.com&#x2F;show&#x2F;8776&#x2F;arm-challinging-intel-in-the-server-market-an-overview&#x2F;9" rel="nofollow">http:&#x2F;&#x2F;www.anandtech.com&#x2F;show&#x2F;8776&#x2F;arm-challinging-intel-in-...</a><p><a href="http:&#x2F;&#x2F;www.cnx-software.com&#x2F;2014&#x2F;10&#x2F;26&#x2F;applied-micro-x-gene-64-bit-arm-vs-intel-xeon-64-bit-x86-performance-and-power-usage&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.cnx-software.com&#x2F;2014&#x2F;10&#x2F;26&#x2F;applied-micro-x-gene-...</a><p>Spoiler: Intel still has the upper hand (for now), at least in perf-per-watt.<p>Even the green500 (<a href="http:&#x2F;&#x2F;green500.org&#x2F;news&#x2F;green500-list-november-2015?q=lists&#x2F;green201511" rel="nofollow">http:&#x2F;&#x2F;green500.org&#x2F;news&#x2F;green500-list-november-2015?q=lists...</a> ) is dominated by Xeon-based clusters.