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Go to SolutionPrecision 5510, CPU running at 0.78 GHz
My Dell Precision 5510 (Intel i7-6820HQ, base speed 2.70 GHz) is consistently running at 0.78 GHz. Here is what I have checked:
Ran Dell ePSA diagnostics: CPU, memory, SSD, fans, charger, and other tested components passed.
Battery diagnostic gave a warning: battery health 37% and reaching end of usable life.
Dell BIOS correctly recognizes the 130W AC adapter.
Checked BIOS: Intel SpeedStep, Turbo Boost, C-States, and Hyper-Threading are enabled.
Windows power plan: Minimum processor state 5%; Maximum processor state 100%.
Task Manager showed 0.78 GHz at idle.
Put the CPU under sustained load: utilization reached about 79% but speed remained at 0.78 GHz.
Disconnecting the charger caused the speed to drop briefly, but it returned to 0.78 GHz.
Question: What could be forcing the CPU to remain capped at approximately 0.78 GHz despite the hardware diagnostics passing? Could the degraded battery cause this, or should I investigate another power/thermal throttling issue?
(edited)
I would check inside before you do that, and remove the battery to see if that fixes the issue (run on AC only). If it doesn't, there's something else in play. The system is over a decade old and could have deterioration in the voltage regulator ICs, for one.
Before sinking money into repairing this system, bear in mind that these sell on EBay at present starting at about $100 complete and working. Even a battery replacement -- particularly with an OEM battery -- is gambling a significant percentage of the value of the system.
ejn63
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Posted July 22nd, 2026 17:48
That rules out the most common cause. Is the system clean inside, and have the thermal pads been replaced (and is the system running abnormally not)?
Do the fans operate normally?