Check the power plan that in use on Windows Server 2008 R2. The default power plan with a clean install of this OS is the Balanced plan. Using this plan (or other power-savings plans) can have a significant effect on Advantage Database Server performance. The negative performance impact seems to be even bigger when CPU utilization is low.
If you think this is the case:
- Change the Power Option to “High Performance” in Windows. Go to the Control Panel, select Power Options, and then choose the “High performance” plan. Alternatively, I think it might be sufficient to change only the Minimum processor state setting, but I have not tested that extensively.
- Also check the BIOS settings and look for something called “CPU Power Management” or possibly “Demand-Based Power Management”. If it is enabled, then disable it. This setting also in some cases compounds the problem and seems to be somewhat independent of the OS power management settings.
- If running under VMWare, check the Power Management option (under the Configuration tab for the Host server). Make sure the policy is set at “High Performance”.
Performance will, of course, vary in many different situations, but testing on one specific machine showed that the above changes (1 and 2) caused a test that appended records to run much faster. With all power management settings enabled, the test took 33 seconds to append 100,000 records. With the power management turned off, the same test ran in less than 7 seconds.
More details about this are in a Stackoverflow question.
