Tool to Evaluate I/O Cost & Performance
Input Values:
CPU MIPS =
MIPS
CPU Cost =
$
Width of interleaved memory =
bytes
Memory cycle time =
ns
I/O Bus bandwidth =
MB/sec
Maximum number of SCSI buses and controllers =
SCSI Bus transfer rate =
MB/sec
Maximum number of disks per SCSI string =
Cost of each SCSI controller =
$
SCSI Controller overhead =
ms
Number of CPU instructions for an I/O operation =
Average I/O size =
KB
Input Disk specifications:
Disk size =
small disk
GB
large disk
GB
Cost of Disk per GB =
small disk
$
large disk
$
Maximum number of disks per package =
small disk
large disk
Disk Rotation speed =
small disk
RPM
large disk
RPM
Average seek time =
small disk
ms
large disk
ms
Disk Transfer rate =
small disk
MB/sec
large disk
MB/sec
Desired total disk capacity =
GB
Cost of enclosure =
$
Constraints on Resource Utilization:
Limit on disk time utilization =
%
Limit on utilization of SCSI buses =
%
Limit on utilization of I/O bus =
%