Your iMac isn’t slow because it’s old — it’s slow because Apple shipped millions of them with outdated hard drives right up until 2019. The good news? A proper SSD upgrade can completely transform performance, cutting boot times from over a minute to seconds and making the whole machine feel new again.

In this guide, we cover the best SSD upgrade options for every iMac generation in 2025 — including internal SSD kits for Intel iMacs and ultra-fast Thunderbolt storage for newer M-series models.

Upgrading your Mac with a new SSD? The OWC Aura Pro X2 and Aura N2 are both excellent choices, but they cater to different needs. The Aura Pro X2 is a high-performance option with blazing speeds, top-notch durability, and broad compatibility, including iMacs. It's perfect for heavy-duty tasks like video editing or gaming. On the other hand, the Aura N2 is a budget-friendly choice that's ideal for everyday use, offering good performance at a lower price. Whether you're looking for speed or savings, this guide will help you decide which SSD best suits your needs.