Abstract
Because of high packing density of hard disks, cooling of future disk array systems using 2.5-inch hard disks is extremely difficult than conventional systems using 3.5-inch hard disks. Accordingly, cooling study of 2.5-inch hard disk array systems is conducted using a mockup model. The mockup has tandem fans for redundant cooling. Heat transfer experiment is performed for the standard type where hard disks are arrayed in rows without any modification of flow channel, and for the frame type where plate with large holes is set between the rows of disks. Heat generation of dummy hard disks is set at 7 W that corresponds heat dissipation in an actual 2.5-inch hard disk for high reliance disk array systems. Maximum temperature increase of dummy hard disks at normal fan operation is less than 15 degree at fan voltage of 9 V(3⁄4 of standard voltage) that meets the cooling specification of hard disks. The maximum temperature increase for the frame type is lower than the standard type by 2 to 5 degree. The cooling specification is also satisfied even when operation of one fan is stopped. The maximum cooling capacity is about 9 W for the mockup model at fan voltage of 9 V, and sound pressure level is less than 60 dBA at the fan voltage, those meet all cooling specification.
