Re: VC++ Compiler multithreading

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"David Wilkinson" <no-reply@xxxxxxxxxxxx> wrote...
Harry Reid wrote:

Is VC++ compiler itself utilize multithreading ?

Because my friend said that his computer "stops" when VC++ is in the
process of linking ...

Is it true that single core process will be better in this case to speed
up the compiling and linking process of VC++ compiler ?

Harry:

You can be sure that all versions of VC++ utilize multiple threads in one
way or another, even on a single CPU machine.

But VS2005 can divide the compilation itself into multiple threads on a
multi-CPU machine. This should make the compilation faster. Why do you say
slower?

During compilation, each individual file is compiled quickly, so you see
activity. The link step does not show incremental progress, so the machine
will appear to "hesitate". This is normal. Unless your friend is seeing
something beyond what I normally observe.

Isn't it the case that VS only distributes a whole solution build across
multiple CPUs/cores? That is, a solution with two projects will build both
at the same time. However the individual files will all build within the
same blocking thread, and hence a solution with a single project doesn't
benefit from this at all. I understood it was a common complaint levelled at
VS2005, that the compiler/project build manager was not efficient across
multiple cores?

Anyway the OP seems to be talking about the linker here specifically. It
certainly has a big impact on my (single-core) machine when linking large
projects, both CPU and HDD activity-wise, and especially when using LTCG.
I've not heard anyone suggest the linker itself has been optimised for
multiple cores yet. One way to tell is to check the Task Manager graphs I
suppose.

--
Andy


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