Updated the readme.

readme.txt

@@ -1,14 +1,51 @@
 A SIMD optimized version of the WELL512a random algorithm.
 
-For a detailed description of how the algorithm works, please see the following pages:
+
+=== OVERVIEW ===
+
+WELL512a is a pseudorandom number generator algorithm developed by
+F. Panneton, P. L'Ecuyer and M. Matsumoto.
+
+This is a fast implementation of that algorithm in C++ using SSE2 intrinsics
+for the x86 / x64 platform.
+
+For a detailed description of how the algorithm works, please see the
+following pages:
 1) http://en.wikipedia.org/wiki/Well_equidistributed_long-period_linear
 2) http://www.iro.umontreal.ca/~panneton/WELLRNG.html
 
-Benchmarking shows that the SSE2 implementation is generally about 2-3 times faster than
-the C implementation by the original authors.
 
-It requires a SSE2 capable CPU (i.e. Intel Pentium 4 or newer, AMD Athlon 64 or newer).
+=== PERFORMANCE ===
 
-All the source code except WELL512a.cpp|h that contains the original implementation
-are released under the BSD license which allows you to include this in any open
-or closed source project.
+This implementation is generally about 2-3 times faster than the C
+implementation by the original authors.
+
+Some example numbers from the included test program run on an Intel Core
+i7-3770K 3.5GHz:
+
+                VS2012     gcc 4.6.3
+C++ SSE2        0.078
+Original C      0.223
+-------------------------------------
+                x2.86
+
+
+=== REQUIREMENTS ===
+
+An SSE2 capable CPU (i.e. AMD Athlon 64, Intel Pentium 4 or newer.
+
+It's been tested with Visual Studio 2012 and gcc 4.6.3 but should compile
+and run on other compilers as well.
+
+
+=== LICENSE ===
+
+All the source code, except WELL512a.cpp|h that contains the original
+implementation, are released under the Simplified BSD license which allows
+you to use this code in any open or closed source project.
+
+
+=== ACKNOWLEDGEMENTS ===
+
+Thanks to Marcus Geelnard for code review and many suggestions for
+improvements.