They're not literally cut in half; the arrays are designed with "jumpers" to disable blocks. But the capacity is halved, so that's why the 64GB dies become 32GB

They're not literally cut in half; the arrays are designed with "jumpers" to disable blocks. But the capacity is halved, so that's why the 64GB dies become 32GB, 16GB, or 8GB cards. (the dies live again!)