Fortran traditionally doesn't set options such as -fp:strict (which ifort requires to enable some of the features in USE IEEE_arithmetic, a part of f2003 standard). Intel C++ also doesn't set -fp:strict as a default, but that is required for ERRNO handling, for example, and other C++ compilers don't make it convenient to turn off ERRNO or gain optimizations such as simd reduction. gcc and g++ have required me to set up Makefile to avoid using the dangerous combination -O3 -ffast-math -fopenmp -march=native. Other than these issues, this question about relative performance gets more nit-picky and dependent on local rules about choice of compilers and options.

大多数帖子已经提出了令人信服的论点，所以我只是在另一个方面加上众所周知的2美分。

在处理能力方面，fortran更快或更慢是有其重要性的，但如果用fortran开发一些东西需要5倍多的时间，因为:

it lacks any good library for tasks different from pure number crunching it lack any decent tool for documentation and unit testing it's a language with very low expressivity, skyrocketing the number of lines of code. it has a very poor handling of strings it has an inane amount of issues among different compilers and architectures driving you crazy. it has a very poor IO strategy (READ/WRITE of sequential files. Yes, random access files exist but did you ever see them used?) it does not encourage good development practices, modularization. effective lack of a fully standard, fully compliant opensource compiler (both gfortran and g95 do not support everything) very poor interoperability with C (mangling: one underscore, two underscores, no underscore, in general one underscore but two if there's another underscore. and just let not delve into COMMON blocks...)

那么这个问题就无关紧要了。如果某样东西很慢，大多数时候你无法在给定的限制范围内改进它。如果你想要更快，改变算法。最后，使用电脑的时间很便宜。人类的时间不是。珍惜减少人类时间的选择。如果它增加了使用电脑的时间，无论如何它都是有成本效益的。

在某种程度上，Fortran在设计时就考虑到了编译器优化。该语言支持整个数组操作，编译器可以利用并行性(特别是在多核处理器上)。例如,

密集矩阵乘法很简单:

matmul(a,b)

向量x的L2范数为:

sqrt(sum(x**2))

此外，FORALL、PURE和ELEMENTAL程序等语句进一步有助于优化代码。由于这个简单的原因，即使是Fortran中的指针也不如C语言灵活。

即将发布的Fortran标准(2008)具有协同数组，允许您轻松地编写并行代码。G95(开源)和来自CRAY的编译器已经支持它。

所以是的，Fortran可以很快，因为编译器可以比C/ c++更好地优化/并行化。但是就像生活中的其他事情一样，有好的编译器和坏的编译器。

我还没有听说过Fortan比C快得多，但是可以想象在某些情况下它会更快。关键不在于语言特征的存在，而在于那些(通常)不存在的特征。

一个例子是C指针。C指针几乎到处都在使用，但指针的问题是编译器通常无法判断它们是否指向同一个数组的不同部分。

例如，如果你写了一个strcpy例程，看起来像这样:

strcpy(char *d, const char* s)
{
  while(*d++ = *s++);
}

编译器必须在d和s可能是重叠数组的假设下工作。所以当数组重叠时，它不能执行会产生不同结果的优化。正如您所期望的，这在很大程度上限制了可以执行的优化类型。

[我应该注意到，C99有一个“restrict”关键字，显式地告诉编译器指针不重叠。还要注意，Fortran也有指针，语义不同于C语言，但指针不像C语言那样无处不在。

但是回到C与Fortran的问题上，可以想象，Fortran编译器能够执行一些对于(直接编写的)C程序可能无法实现的优化。所以我不会对这种说法感到太惊讶。不过，我确实希望性能差异不会太大。(~ 5 - 10%)

This is more than somewhat subjective, because it gets into the quality of compilers and such more than anything else. However, to more directly answer your question, speaking from a language/compiler standpoint there is nothing about Fortran over C that is going to make it inherently faster or better than C. If you are doing heavy math operations, it will come down to the quality of the compiler, the skill of the programmer in each language and the intrinsic math support libraries that support those operations to ultimately determine which is going to be faster for a given implementation.

编辑:@Nils等人提出了一个很好的观点，即C语言中指针使用的差异，以及可能存在的别名，这可能会使C语言中最简单的实现变慢。然而，在C99中有一些方法可以解决这个问题，比如通过编译器优化标志和/或C语言的实际编写方式。这在@Nils的回答和随后的评论中有很好的介绍。

I was doing some extensive mathematics with FORTRAN and C for a couple of years. From my own experience I can tell that FORTRAN is sometimes really better than C but not for its speed (one can make C perform as fast as FORTRAN by using appropriate coding style) but rather because of very well optimized libraries like LAPACK (which can, however, be called from C code as well, either linking against LAPACK directly or using the LAPACKE interface for C), and because of great parallelization. On my opinion, FORTRAN is really awkward to work with, and its advantages are not good enough to cancel that drawback, so now I am using C+GSL to do calculations.