What is power consumption of Dell 2950?

750W/1500W(single/redundant power supplies) , as per the DELL spec sheet. Actual power consumption will vary based on fan speed, number of hard drives, system load, etc.

"AC configuration with standard single or redundant 750W hot-plug auto-switching universal 110/220V AC power supplies DC configuration with single or redundant hot plug -48 to -60 V20 A DC power supplies"