If you believe you've optimized your Delphi application to the max, and there is no room for performance improvement, then you should check out following site: http://sourceforge.net/projects/fastcode
Project Fastcode is competition of assembler developers on rewriting certain Delphi RTL functions to processor-specific code, utilizing extra instruction sets like SSE, SSE2, etc. This way Fastcode winners achieve 2x-4x performance boost compared to classic i386 implementations.
Each function in Fastcode project has 5 variants, each variant is optimized for certain processor architecture:
I have put together a package allowing you start on using Fastcode just in 5 mins. It contains units that auto-determine your CPU type and auto-patch VCL to use Fastcode. The following Fastcode functions are included:
I recommend using this package in non-GUI application servers, facilitating strong memory usage, etc.
Despite it will not make your application incredibly fast, overall speed up will be about 5%.