Mine claims about 25 mins to power down with a resting pull of 240 watts, 15 mins while using GPU for SD or AI stuff (400 watts). The key importance in my mind though isn’t the time to shut down, but how long term dirty power will cause failure in your components. I learned this the hard way back in the C-64 days where I went through 3 of them (Circuit City warranty covered them) before I got a very crude version of a UPS to stop killing the poor computer with ups and downs in power surges.