Accelerating Scientific Computations with Mixed Precision Algorithms
  On modern architectures, the performance of 32-bit operations is often at least twice as fast as the performance of 64-bit operations. By using a combination of 32-bit and 64-bit floating point arithmetic, the performance of many dense and sparse linear algebra algorithms can be significantly enhanced while maintaining the 64-bit accuracy of the resulting solution. The approach presented here can apply not only to conventional processors but also to other technologies such as Field Programmable Gate Arrays (FPGA), Graphical Processing Units (GPU), and the STI Cell BE processor. Results on modern processor architectures and the STI Cell BE are presented. 
Marc Baboulin, Alfredo Buttari, Jack Dongarra, Jakub Kurzak, Julie   Langou, Julien Langou, Piotr Luszczek, and Stanimire Tomov