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Testing I/O performance

This tip links to Intel's free Iometer program, allowing you to test storage products on NT 4.0/Solaris operating systems.

Do you know how well your storage systems are performing? It's one thing to look at the specifications that manufacturers provide, but are you getting the most you can from your disk drives, tape drives and so forth?

You can test it. There is at least one test program available that's free. It's Intel's Iometer (pronounced eye-OM-eter) and it's available from the Intel web site. If you're running Intel-based servers with NT 4.0, you can use Iometer. (There is also a Solaris version of Iometer in the download ZIP file.) The program is old, (latest version dated 1988) but it's very useful. And even though it is old, I just installed and ran it on a Sony notebook computer running Windows 2000 Professional.

Iometer isn't designed to test a lot of parameters, but it will tell you how fast you can shuffle data into and out of your system to some device, such as a disk drive. Here's what Intel says about this very useful tool.

Iometer is an I/O workload generator and performance analysis tool for single and clustered servers. It works like a dynamometer for server I/O: it measures the I/O performance of the system while stressing it with a controlled workload. You can configure Iometer to simulate the workload of any real-world application or benchmark, or create a completely artificial workload to stress the system in specific ways. Iometer will accurately and reliably reproduce any workload you specify, while gathering data such as throughput, latency, and CPU utilization. By running the same workload on multiple system configurations, you can determine the strengths and weaknesses of each and select the optimum configuration for your needs.

Depending on how you use it, the program will allow you to compare lots of products and systems. I used it extensively when I was running the VARBusiness Labs, in a previous job. By varying only the disk drive attached to a particular controller, I was able to determine which was the fastest in a given scenario of load and activity. Similarly, you can compare servers, I/O controllers, communications channels, etc.

Iometer can be downloaded for free. All Intel requires is that you download your own copy of the program, and that you don't give it to anyone else. The company also wants feedback on the program so it can be improved. And Intel will not, of course, certify nor guarantee any results you get. They're for you to use as you see fit.

David Gabel is the executive technology editor at

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