Removing the storage I/O bottleneck enabled Twitter to reduce the total number of racks in its cluster, which gives the company a smaller data center footprint. They achieve that density by moving from 12 smaller to 8 larger hard drives per system, which reduces the number of hard drives in a cluster without negatively impacting performance. And by removing the hard drive performance bottleneck, they were able to take advantage of more CPU horsepower, so they moved from 4-core processors to 24-core processors. The combination of the larger hard drives and higher-core-count processors means they can reduce the number of systems, hard drives, and racks in each Hadoop cluster in their data center, which leads to reduced maintenance costs and much better energy efficiency. It’s also great for the environment that we can produce the same results with about 75% less energy. Caching temp data and bumping up processor core counts is expected to result in up to 50 percent faster runtimes, and the increased density results in 30 percent lower TCO. This sets Twitter up to be ready for continued growth of its data, while still delivering the great experience their users expect.