Both flagship PSU series from Corsair boast very high efficiency, quiet operation and low voltage ripple. There are but minor differences between them.
Based on a Seasonic platform, the AX series is somewhat better in terms of voltage stability, efficiency at low loads, noisiness at high loads and standby voltage. They are also less expensive than their AXi counterparts.
The Flextronics-based AXi PSUs are overall more efficient and have weaker voltage ripple, but their key feature is the Corsair Link interface that offers monitoring and setup opportunities.
Every model we’ve discussed in this review deserves a place in a high-efficiency computer. The AX series is going to be optimal if you need basic functionality without any extras. The extended functionality of the AXi models isn’t so expensive, though. It is about 10% of the PSU price. We guess that’s not much for the opportunity to check out the Corsair Link capabilities. You may find them highly useful.