I've been experiencing a problem with my processor's speed lately.
The CPU is running 797MHz, instead of it's full performance. In the past, it's been running well, until yesterday when it suddenly became slow.
What I already tried:
- Turning on/off Intel SpeedStep
- Turning on/off Turbo
- Clearing cmos
- Setting bios settings to default
- Running the PC with and without the battery
- Reinstalling windows
- Setting the power plan to high performance; setting the minimum processor state to 100%
Because of that, the CPU is unable to really heat up even during a stress test. It also stays at this slow state during a stress test and full load. During a stress test, one would usually expect the temperature to rise and the fans to speed up, yet it doesn't happen. The issue is making the computer quite slow. Basically, the cpu is somehow limited.
Here are some screenshots: CPU-Z + HWInfo; The BIOS
The processor is Intel Core i7-2820QM; the computer is Alienware M18X R1 Laptop running Windows 10. Warranty is expired. I am using integrated graphics.
Why is the CPU unable to run at full speed and how do I fix this? Should I increase the bus clock frequency? The PWR limits?
Best Answer
You CPU is running in idle mode, which is multiplier 8 : 800 MHZ = 100 * 8. The CPU-Z report shows that its is capable of reaching up to a 34 multiplier, which is 3400 MHZ, and HWINFO says the same.
As a first test, you could run the Intel® Processor Diagnostic Tool, although I don't really expect it to find anything.
Second, have you opened your computer lately? There a switch on the motherboard which tell the CPU to always run at the lowest speed. This switch is called Slow mode or LN2 Slow Mode or OC Trigger Switch (TGR) or else. You might find its description in your motherboard's manual. It is sometimes situated right next to the power reset button. Even if it on the right position, sometimes just moving it between positions corrects the problem.
There might also be BIOS settings that disable the CPU thermal monitoring if it became defective. These might be called EIST and/or Intel Adaptive Thermal Monitor. If this helps then something is wrong with your motherboard.
Another such setting is BD PROCHOT (Bi-directional Processor Hot), an emergency throttling system that is used when a CPU hits its maximum temperature. To disable it temporarily, download ThrottleStop to check on and disable BD PROCHOT. ThrottleStop when running can also correct several types of CPU throttling. Again, if this helps then something is wrong with your motherboard.