You need some form of unbounded while loop for Turing completeness, but it can take many forms.
Also, in a high-performance setting, a surprising number of programs do not need recursion (and hence Turing-incompleteness) at all. In the vast majority of the Futhark programs I've written, `while` loops are either not used at all, or used for something fairly simple like an outermost convergence loop (and typically with a iteration bound anyway, so it could be written as a `for` loop with early exit).