Optimizing 64-Bit Programs  Optimizing 64-Bit Programs  Andrey
Karpov "Program Verification Systems"   Some means of 64-bit
Windows applications performance increase are considered in the
article.   People often have questions concerning 64-bit
solutions performance and means of increasing it. Some
questionable points are considered in this article and then some
recommendations concerning program code optimization are given.
1. The Result of Porting to 64-Bit Systems  In a 64-bit
environment, old 32-bit applications run owing to the Wow64
subsystem. This subsystem emulates a 32-bit environment by means
of an additional layer between a 32-bit application and the
64-bit Windows API. In some localities, this layer is thin; in
others, it's thicker. For an average program, the productivity
loss caused by this layer is about 2%. For some programs, this
value may be larger. 2% is certainly not much, but you still
have to take into account the fact that 32-bit applications
function a bit slower under a 64-bit operat