CPU performance drops under 0.5 GHz
CPU performance drops under 0.5 GHz
I own an HP Pavilion 15-inch with an i7-8550U processor. It sometimes drops to under 0.5 GHz without any apparent cause. While watching a YouTube video, the playback becomes very choppy and starts buffering. In Task Manager it shows the clock speed around 0.39 GHz. The temperatures are normal at about 55 degrees. The base speed is 2.0 GHz, but when throttling heavily it hovers near 1.75 GHz, which is still below optimal. Occasionally it runs smoothly between 2.5 to 3.5 GHz.
When correctly configured, the 8550U becomes a powerful processor. Mastering ThrottleStop 9.2 lets you control its performance to your preference. The newest release unlocks the hidden Windows High Performance mode, preventing unnecessary speed increases. Modern CPUs shouldn’t be slowed down unnecessarily. Many brands still believe this method conserves energy, but it often has the opposite effect. A sluggish CPU wastes resources. With a high-performance setup, your laptop can handle tasks swiftly, minimizing time in active processing and maximizing low-power operation. In its idle state, the core operates at zero frequency and zero voltage, achieving significant savings without sacrificing performance.
When examining my previous screenshot, the 8550U operates with multipliers ranging from 37 to 40 under idle conditions. A 40 multiplier applies when one or two cores are active, while a 37 multiplier is used for three or four cores. These settings represent the standard configurations for this processor. Are you experiencing similar behavior when connected to power or operating on battery? Which Windows power plan are you employing? Have you attempted to switch to the High Performance plan using ThrottleStop? Is Speed Shift enabled (SST in green) and has the Speed Shift EPP option been activated at 0? These factors determine how your CPU handles light workloads. Please share screenshots of your ThrottleStop configuration, including the main interface, TPL view, and FIVR display.
It seems there might be some confusion. The performance monitor isn't giving accurate data. The CPU can only operate at 800MHz when idle. Consider using another monitoring tool for better results.
It's a budget U-series processor with a low power design. The smallest possible clock speed it can reach is 400 MHz. https://h30434.www3.hp.com/t5/Notebook-H...ook-470-G5 Edit - Initially assumed the minimum multiplier was 5, but CPU-Z indicates it's actually 4.
The 800 MHz specification refers to the CPU entering adjustable power limits. The 8550U can reduce to 400 MHz. When Speed Shift Technology is active, performance varies based on the Windows power plan and BIOS configuration of its speed settings. The Lenovo laptop I tested limits itself to a maximum of 900 MHz. Operating below this may lead to poor performance. Applying ThrottleStop to fine-tune the Speed Shift Min and Max values provides users with greater control over CPU behavior. Incorrect settings can cause the CPU to remain stuck at 400 MHz even under heavy workloads.
There seems to be an issue since adjusting throttle or Intel XTU doesn't affect the performance. Previously it stayed above 2 GHz, but now it often drops to around 1.5 GHz or less most of the time. Turning off BD ProChot didn't reduce throttling significantly either, and it still operates below the base clock speed. This behavior hasn't occurred before, and no changes were made when it started.