I recently got my X220 i7 2620m (4286) and using the Windows System Assessment Tool (WinSat) I received the following WEI (Windows Experience Index) scores for my system:
Memory Ram: 5.6
Gaming graphics: 5.7
Primary hard disk: 5.9
All my drivers are up to date and the BIOS version of my system is 1.26. What could have caused the scores to be so low?
Ensure that you run the test with your battery plugged into your system, on AC. The standard AC adapter fro the X220 delivers 65 watts of power . Some users report higher performance with the 90-watt AC adapter. The latest versions of the BIOS optimize power utilization so that the performance even with the 65 watt adapter will be close to 90%-95% of that when using the 90 watt adapter. If the battery is removed from the system, and the 65 watt adapter is used on the X220 or many earlier models, the CPU will not achieve maximum performance - this is a design limitation imposed to protect against the risk of shutdow if the total power draw of system and attached devices (USB, docks, etc) exceeded 65W.
Be sure that your settings in Power Manager are set to Maximum when you run the Windows experience test.
You may also wish to check for background tasks that could be impacting CPU performance. To determine if any processes are consuming CPU time in Task Manager, press CTRL+SHIFT+DEL to bring up the windows menu, select task manager and look on the bottom for CPU Usage. The processes tab will help you identify which tasks may be drawing CPU time and detracting from the index scores.
For more information about WINSAT, please refer to this.