https://wccftech.com/base-model-m1-imac-cannot-be-configured-with-2tb-ssd-limited-to-1tb-only/

If you plan on getting the base model 24-inch M1 iMac, then you should know that you cannot configure it with 2TB of storage space.

We know that the new M1 iMac cannot be configured with 32GB of unified memory. We also know that you have to pay $50 extra if you need the Touch ID keyboard. We also learned that the base model iMac ships with just two USB 4 ports. Now we are learning that you cannot configure it with more than a terabyte of storage.