Purpose of Review <p>The purpose of this review is to assess the current state of research into data center flexibility, and its potential.</p> Recent Findings <p>There are several mechanisms by which data centers can provide flexibility including: protection systems, pre-cooling, altering CPU/GPU clock rate, and “smart” job scheduling. The latter being most popular in academic research. Much research specifically investigates cryptocurrency mining due to its continuous and interruptible nature.</p> Summary <p>While many researchers propose mechanisms for increasing data center flexibility, comparatively little is understood about its potential scale or cost. Some research suggests that operators are unwilling to provide flexibility, and we demonstrate using real energy usage data that centers are not likely to be sensitive to electricity price, aside from during extreme events. Cryptocurrency mining is inherently flexible, but is mostly performed on specialized hardware (not in traditional data centers) and its price sensitivity fluctuates with currency exchange rates.</p>