i7: Quad-core processor only runs on one core - what to do?
If your Intel Core i7 processor only runs on one instead of four cores, this can have various causes. This practical tip shows you how to check and correct the error.
How to check the number of cores used by Windows
If you only suspect that your i7 processor is only running on one core - for example because you are not satisfied with the performance - you should first check the number of cores actually used:
- Press the key combination [Ctrl] + [Alt] + [Del] and select the "Task Manager".
- Switch to the "Performance" tab and click on "CPU" on the left side.
- In the right area of the window you can now see the number of cores used by Windows. Your quad-core processor should say "Cores: 4".
Faulty system configuration limits CPU to one core
In most cases, an incorrect system configuration is responsible for ensuring that your quad-core processor only runs on one core. Fortunately, the problem can be fixed quickly:
- Press the key combination [Win] + [R] and type in "msconfig" (without quotation marks).
- Switch to the "Start" tab and click on the "Advanced Options ..." button.
- Make sure that the "Number of processors" is not checked. You may have to remove the check mark. You apply your changes with the OK button. Then restart Windows.
Define affiliation for individual applications
If only certain programs only run on one core, you may have to define their affiliation in the Windows Task Manager:
- Press [Ctrl] + [Alt] + [Del] and select the "Task Manager".
- Go to the "Details" tab and right-click on the application that only runs on one processor core. In the context menu, select "Set affiliation".
- Make sure that all checkmarks are set in the new window. Then click on "OK".
Further tips if not all CPU cores are used
- Download and install the latest drivers for your motherboard.
- If you have recently changed BIOS settings, you should undo them or reset the BIOS to the default values.
- Make sure that the BIOS of your motherboard is up to date and carry out an update if necessary.
- Programs such as Process Lasso or System Explorer can also restrict the use of the processor cores. If you use such a program, check its configuration or remove the program again.
In our next practical tip, we will show you how to activate the Intel Turbo Boost of your Core i7.