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Altera_Forum's avatar
Altera_Forum
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16 years ago

Will Quartus generate same timing results if a build is run twice?

If a design is P&R with Quartus, will it give same timing result for two builds if no parameter is changed for either build? No RTL change, no SDC change, no SEED change.

I would think it should.

5 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Yes. There are no random variables that go into the compile, so the results will be the same. (Operating Systems will affect it though, due to different floating point math results. All Windows should be the same, but different than Linux compiles. Same thing as a different seed though, i.e. one is not better than the other.)

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    --- Quote Start ---

    All Windows should be the same, but different than Linux compiles.

    --- Quote End ---

    I'll just add that 32-bit and 64-bit compiles will also give different results, again since the compilers are different. So win32, win64, lin32 and lin64 will all give different answers from one another, but (as Rysc said) these are just equivalent to a change in seed.

    Just to reiterate what everyone else has said: yes, if Quartus is run twice on the same inputs on the same OS, it will always give the same results.

    Adrian Ludwin

    Altera Corp.
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    FYI if a post helps you give the user reputation points. Every time I see short posts like yours my first thought is "is this spam?" (I almost banned you.... good thing I searched your other posts before I brought down the hammer :))