How to use IOMETER

Yes, IOMeter is one of great tool for measuing storage or network performance testing, although it is old.

* Windows version only

 

1. Install

2. Prep for testing

2-1 Be Administrator privilege on the computer

2-2 Disable ‘Write-caching policy’ on your HDD/SSD

 

“Write caching” in a storage device refers to the use of high-speed volatile memory to collect write commands sent to data storage devices and cache them until the slower storage media (either physical disks or low-cost flash memory) can accommodate them. Most devices that use write caching require that power be supplied continuously

 

Write through

 

 

* Write caching/Wite-back?  The operating system sends data to the controller to write to a storage device. Subsequently, the controller sends a confirmation to the operating system before actually writing the data to the storage device(such as the hard disk or flash memory). Lost of power, casuse lost of data.

 

** Write through? opposite of Write-back. Less data transfer performce, but no risk of data lose.

 

 

*** Cache flushing? This means that the system will periodically instruct the storage device to write all data waiting in the cache to the storage device.

 

 

 

2-3 Testing file, iobw.tst should be created on C:\

un-partitioned disks (blue icon disk)- can test without testing file

formatted disks (yellow icon – cannot test without testing file

 

TestFileCreator.exe to create a file.

 

Ex) Testfilecreator 10G

 

 

2-4 Sector parameter, calculated with 512B instead of 4KB.

 sector = 512 bytes; 20971520 = 10GB

If you leave Maximum Disk Size at 0 it’ll use all free space on the drive. This results in quite a few write operations and may make later tests show degraded performance. Be sure to enter a value in "Maximum Disk Size". The number entered is the number of sectors to use. (Standard: 512 bytes / sector; Advanced Format: 4096 bytes / sector; Standard Drives: 20971520 sectors = 10GB)

 

 

3. Opentions.

 

Enter "4" for "# of Outstanding I/Os

 

Normal workstation = 70% reading / 30% Writing / 70% Random / 30% sequential

 

4. Testing result reference

 

 

 

IOPS
Disk Speed	Min	Median	Max
SATA 5400	40	55	75
SATA 7200	75	88	100
SATA 10000	125	138	150
SAS 10000	140	140	140
SAS 15000	175	193	210
SSD	10000	55000	100000

 

 

RAID Write Penalty
RAID	Penalty
RAID 0	0
RAID 1	2
RAID 5	4
RAID 6	6
RAID 10	2

 

 

 

 

IOPS Per Disk Type = http://en.wikipedia.org/wiki/IOPS

IOPS Formula = http://www.yellow-bricks.com/2009/12/23/iops/

RAID Types = http://en.wikipedia.org/wiki/RAID