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So far, I used the general matrix MKL function dgemv to perform the entire matrix multiplication by the vector while zeroing out the upper triangle of the matrix values so these elements have no effect upon the result vector.

Behind the scenes, what's the difference between using dgemv as I described above and dtrmv to perform this operation? Is dtrmv faster? Without using parallelism which MKL function is the fastest one to use for my operation?

Thanks.

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Hello,

dtrmv will only use upper or lower triangle data, but it does not assume the upper or lower triangle data is 0. For your case, it looks you can zero the upper data, and then use dgemv. But using dtrmv, it may create a different result.

Thanks,

Chao

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Hello,

yes, dtrmv multiplied less elements as it is assuming the symmetric matrix, the dgemv will take the full matrix for multiplication. But have you checkif the result is right for you?

Thanks,

Chao

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Thanks for the responses.

Blake

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