↑Note: Assuming DDR RAM takes on the order of 1W/1 GB DIMM, then 4GB I-RAM will take 4W, plus power for controller, battery, etc., compared to 0.9 (idle) to 3W (working) for a 250GB laptop hard drive. Also the I-RAM continues to use power 24/7, where a hard drive only uses power when it is on.