cargo test --release causes a stack overflow. Why doesn't cargo bench?

In trying to write an optimized DSP algorithm, I was wondering about relative speed between stack allocation and heap allocation, and size limits of stack-allocated arrays. I realize there is a stack frame size limit, but I don't understand why the following runs, generating seemingly realistic benchmark results with cargo bench, but fails with a stack overflow when run with cargo test --release.

#![feature(test)]
extern crate test;

#[cfg(test)]
mod tests {
    use test::Bencher;

    #[bench]
    fn it_works(b: &mut Bencher) {
        b.iter(|| { let stack = [[[0.0; 2]; 512]; 512]; });
    }
}