While the M4 Mac mini's $599 starting price is attractive, the base model's 256GB storage can be limiting. However, one modder has demonstrated how to upgrade the storage to 2TB by replacing the NAND chips, a process requiring advanced soldering skills.
YouTuber and hardware modder dosdude1, known for circumventing Apple's soldered storage limitations, tackled the M4 Mac mini's storage. The base model's 256GB SSD module actually consists of two 128GB NAND chips for enhanced performance. Initially aiming for a 2TB upgrade using two 1TB NAND chips, dosdude1 encountered a faulty batch, ultimately achieving a 1TB upgrade with two 512GB chips.
This modification bypasses Apple's $400 upgrade fee for 1TB of storage, offering a significant cost saving for those with the necessary skills. The video (below) details the entire process.