Re: small i & power systems (disk performance)

Keith Carpenter wrote:

System experts,

We are looking to move an old 640 with 72 8gb disks to a new low end system. CPW should be no issue, but I'm concerned about disk IO performance in these 520+/515/525 systems.

I had hoped to go with an 8 disk system (CEC only), but from what I've read in the archives, you need an expansion box to be able to use a better RAID controller. How much of an improvement would a 0595 and something like a 5777 actually make over the integrated controller (w/5727 cache) ?

Does the new power 520 offer anything better ? Is the integrated SAS controller much of an improvement ? Can we put a better RAID directly in the CEC ?


TIA,
Keith

You need to collect some basic performance data.. Mainly how many Disk I/O per second you are doing now under your normal load conditions. The 8GB drives 'MIGHT' me 10K at best and the controllers may have 104MB cache depending on the card. The SAS drives are 15K and according to IBM are 10% to 15% faster than their SCSI counter parts.

According to PPT slide I have the internal raid controller can handle 1100 to 1400 I/O per second as long as individual drives do not exceed 110 I/O per second