Our software does lots of floating point linear algebra (CFD modeling). Many operations require double precision for larger size matrices. Unfortunately the performance we have been getting out of both Intel and AMD processors was very poor: double precision was almost 2x slower than the same code when using single precision.
We tested the software both under 32-bit and 64-bit Windows (and compiled with corresponding 32 and 64 bit options) with no visible difference. Are there compiler options that we are missing that could speed up double precision computations?