Time taken to run the tests

[andrew wilde]

Sorry if this has been asked and answered in the past, but I am currently trying to CPU benchmark two servers and I am having a few problems.

The servers are both 4 x 1.9Ghz Xeon CPU machines with 4GB memory, essentially exactly the same as each other. The difference is that one is using VMWare to host one Windows 2003 server with all resources assigned to this instance and the other is running Windows 2003 server natively.

What I have found is that the time taken to actually run the tests varies wildly between the two; the physical machine runs about 10x quicker, however the CPU results are roughly what you would expect with a small performance increase over the virtual machine.

Should I be worried that the tests take so much longer to run?

[Michael (Passmark)]

Can you be more specific about which tests are taking longer to complete. Some tests run for a fixed amount of time regardless of the performance, whilst other tests can vary a bit.

Also, do both setups have the same "Test Duration" set in the preferences window?

[andrew wilde]

Time taken to run CPU-All test

Hello,

sorry I wasn't more specific. I was running the test under the CPU menu titled All. I believe this runs all the CPU specific tests one after the other. It was these tests which took 10 times longer on the virtual server than the physical server.

cheers, andy

[andrew wilde]

Test Options

Sorry, every test option was exactly the same on each machine; they were left at the default values.

[Michael (Passmark)]

The CPU tests should all run for a fixed duration regardless of the speed of the system. The scores are determined by a formula that is basically;

amount of work done / total time of test

So if the scores are roughly the same then the two machines are in fact processing at about the same speed.

There are two possibilities for the difference in time taken. The first, as I've mentioned is that the preferences are different between the machines, although you've said this isn't the case (you could try changing and reapplying just to be sure, one of the config files might have become corrupted).

The other possibility is that there is some disparity in the time it takes to initialise the tests (before the actual test timer starts). At the start of each test PerformanceTest launches a bunch of extra processes (as defined in the preferences window). Usually the time to do this is trivial however there may be something about your VM that is causing this to happen slowly. There's in built way of monitoring this (we've never seen it take any significant amount of time) however you can open task manager and see how long it takes for the pt1.exe's to appear and start putting load on the CPU.

[andrew wilde]

Settings file issue

Hi Michael,

Thanks for your help - I did what you said with the settings (I changed the test to medium, clicked ok to close the dialog, opened the preferences again and changed back to short) and that did the trick. Thanks again.

cheers, andy