"We did the back-of-napkin math on what ramping up this experiment to the entire brain would cost, and the scale is impossibly large — 1.6 zettabytes of storage costing $50 billion and spanning 140 acres, making it the largest data center on the planet."
Look at what they need to mimic just a fraction of our power.
It’s not even complete. You might have the physical brain tissue, but that tissue is stateful. The tissue contains potentials and electrical charges that must be included in a complete model.
Just gotta lower the clock speed enough for us not to notice. As long as we don’t interact with the outside world, just other stored human brains, it can be slow as molasses and we won’t notice.