An anonymous reader writes: LMAX Exchange is one of a growing number of firms to use Java in a low latency environment. It has become well known, even outside of financial services, at least in part by dint of being willing to talk publicly about technology choices. The firm open-sourced a key component of its software stack, the Disruptor framework, in March 2011. At the end of last year, LMAX Exchange completed the latest re-build of its production data centre, moving from Hewlett-Packard servers with Intel's HexaCore Dunnington processor to Dell 520 and 720 with dual socket, 8 core, Intel Sandy Bridge CPUs. The Dells have 64 and 128 GB of memory respectively. CentOS 6 is used as the OS. Recently the firm have begun testing Azul's Zing JVM in place of Oracle's HotSpot as a way of improving their already impressive response times and throughput rates. The results are impressive; a 10-20% improvement in the mean latency, increasing to around a 50% improvement at the 99th percentile.