It's worth noting that the 850w PSU won't be enough for a 4090. In fact I would argue it's not enough for your current GPU of choice. With transient spikes etc in mind it should be at least 1000w but I would want an ATX3 PSU in such a system. It's a shame you never asked here before purchasing as we could have saved you a number of headaches. The drive selection is far from optimum also.