Hi Lale, One would expect to find it here: http://h10010.www1.hp.com/wwpc/me/en/sm/WF06c/A1-1769079-1769113-1769113-1769139-1769139-16169139.html Nothing really available on their site... However, estimate IOPS is relatively easy with Spindle IOPS = ((RPM/60)/3)*2 Or at least ~167 8k IOPS per spindle To figure out User Data Transfer rates, use the following: UDT=(Spindle Speed / 60 * Sectors Per Track * Bits per Sector * 8) / 1,000,000 Bits Per Sector as defined by HP can be here: http://h18000.www1.hp.com/products/quickspecs/11531_div/11531_div.HTML <http://h18000.www1.hp.com/products/quickspecs/11531_div/11531_div.HTML> So BPS=512 The other two number we need is the platters used in this 146GB drive and the physical platter size (3.5", 2.5", 1", and I would assume 3.5") to determine an areal density or at least GB/Platter density to determine the inner & outer range of UDT. It will be a wide range considering Zone Bit Recording (ZBR) BTW, the whole U320 MB/Sec transfer is a U320 SCSI transfer rate and not the user data transfer rate for the drive itself. Michael Erwin Hotsos Enterprises, Ltd. http://www.hotsos.com Hotsos Symposium 2007 / March 4-8 Visit www.hotsos.com for curriculum and schedule details... ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx on behalf of lale obradovic Sent: Thu 9/28/2006 12:19 PM To: oracle-l Subject: IO rate for U320 SCSI 15K RPM Hard Drive Hi All, Does anyone have some information of expected IO rate (IOPS and/or MBPS) for U320 SCSI 15K RPM Hard Drive (HP 146GB U320 15K Universal HDD)? Thanks! Lale