I have an i7-14700K installed in an MSI PRO B760M-P DDR4 motherboard, along with a Samsung 980 1TB SSD, an RTX 5060 Ti, and Windows 11. The issue began after I replaced the motherboard with another board of the same model; the original board was damaged when I accidentally bent pins while installing a contact frame. The BIOS is fully updated, but during Prime95 the CPU stays around 3.00 GHz instead of boosting. CPU temperatures remain below about 70°C. What could be causing this throttling?
3 Answers
Check the CPU cooler and temperatures first, but a reported peak around 70°C makes normal thermal throttling unlikely. Monitor package power, core clocks, and the motherboard VRM or MOS temperature with HWiNFO while Prime95 is running. If the VRM temperature or power-limit indicators are triggering, the motherboard is the likely cause. Pointing a fan directly at the VRM area could also confirm whether its power delivery is overheating.
The most likely limitation is the motherboard's VRM. That B760M-P model lacks substantial VRM heatsinking and may not be able to sustain the power draw of a 14700K during an all-core workload. The board can protect itself by reducing the CPU to around 3 GHz even when the CPU temperature looks fine. A board with stronger VRMs and proper heatsinks, such as the larger B760-P version, would be a better match. For now, lowering the CPU power limits may help.
Resizable BAR and XMP will not normally explain an all-core Prime95 clock speed of 3 GHz. Since the problem started with the replacement board and only appears under heavy CPU load, inspect the BIOS power limits and VRM throttling flags. The board may be enforcing conservative limits to protect its power circuitry; enabling XMP is optional and unrelated to this specific issue.
Resizable BAR is enabled, while XMP is currently disabled. In FurMark the CPU only reaches about 2–4% usage, so the clock drop is mainly visible during a sustained CPU workload like Prime95.