```markdown
## Primal-dual interior-point methods

- More efficient than barrier method when high accuracy is needed.
- Update primal and dual variables at each iteration; no distinction between inner and outer iterations.
- Often exhibit superlinear asymptotic convergence.
- Search directions can be interpreted as Newton directions for modified KKT conditions.
- Can start at infeasible points.
- Cost per iteration same as barrier method.

*A. d'Aspremont. Convex Optimization M2.*  
Page 34/36
```