PowerEdge 2950 Redundant Power Supplies

From what I understand about the switching power supplies commonly used in computers, they only draw as much juice from the mains as the load placed upon them demands, the power they consume at idle and at moderate server loads is only a small portion of the grand total maximum rating. Whenever a server like the 2950 has dual redundant power supplies installed, then whatever the total current load the whole machine is configured to consume will be spread across the two power supplies. For example if the total combination of disk drives, processors, memory, and server load might be consuming a total of 500 watts, then each of the redundant power supplies will be handling 250 watts. If you suddenly unplug one of the power supplies, then all 500 will suddenly have to be supplied thru the one remaining power supply (which, if I remember correctly each of these power supplies can handle a max of 750 watts). The machine would never consume a steady 1500 watts thru dual power supplies unless something was very, very wrong happening.... you'd probably see it releasing smoke before that.

Thats right, both PS work in tandem evenly distrubiting the load. Average draw per PS in most config's is 350 per unit. Max draw would likely hover around 700 combined in a 2950 as the hard drives, memory and additional cpu would be hard pressed to pull that much wattage given the expansion opportunity. In a 6850 or 2900...well thats a different story.

Message Edited by Canada101 on 10-24-2006 02:18 PM

Thanks, this helps confirm. I sort of knew that it would be insane for the 2950 to draw 1500 wats. But I couldn’t find any info on it.