Hello,
 
I am using serial PETSc linear solver in a serial Fortran program, which uses 
function CPU_TIME() to count cpu time. In Windows-7, the cpu time turns out to 
be 2 to 3 times as much as elapse time. My questions are:
 
1. Does PETSc internally use multi-thread even though I configured it with 
--useThreads=0? I ask so since it is known that CPU_TIME()  adds the cpu time 
of all threads togather.
2. The same program gets consistent cpu time and elapse time in Linux. Do you 
have any idea why?
 
Thanks for any suggestions.
Qin

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