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OLCF support consultants are available to respond to your emails and phone calls from 9:00 a.m. to 5:00 p.m. EST, Monday through Friday, exclusive of holidays. Emails received outside of regular support hours will be addressed the next business day.

Debugging and Optimizing Code on Titan

See this article in context within the following user guides: Titan

There are a number of code debugging and profiling tools available to users on Titan. This section will provide some general guidelines which should apply broadly to all applications, however, the focus will be on applications running on the Titan XK7 system.


DDT is the primary debugging tool available to users on Titan. DDT is a commercial debugger sold by Allinea Software, a leading provider of parallel software development tools for High Performance Computing.

For more information on DDT, see the DDT software page, or Allinea’s DDT support page.

Optimization Guide for AMD64 Processors

AMD offers guidelines specifically for serial code optimization on the AMD Opteron processors. Please see AMD’s Developer Documentation site for whitepages and information on the latest generation of AMD processors.


CrayPAT is a profiling tool that provides information on application performance. CrayPAT is used for basic profiling of serial, multiprocessor, multithreaded, and accelerated programs. More information can be found on the CrayPAT software page.

File I/O Tips

Spider, the OLCF’s center-wide Lustre® file system, is configured for efficient, fast I/O across OLCF computational resources. You can find information about how to optimize your application’s I/O on the Spider page.