8086k overclocking adventure on air

Discussion in 'Overclocking & Cooling' started by VoodooRufus, Jan 10, 2019.

  1. VoodooRufus

    VoodooRufus n00bie

    Messages:
    20
    Joined:
    May 23, 2017
    So I got new toys to play with. Gigabyte Aorus Master mainboard, Intel 8086k delidded Silicon Lottery CPU, using a Dark Rock Pro 4 heatsink.

    I left everything on auto, set the CPU wattage limit to 250W, and then started jacking up the multiplier. The mainboard automatically ramped CPU voltage depending on the clock rate, pretty aggressively once I got past 4.6GHz. Did some 30-45 minute prime95 runs to test initial stability. I manually played with the fan settings to get a good balance of noise/airflow/temps. After 70C I have the CPU and chassis fans running 100%, which is still a low hum. Anything under 60C is nearly silent.

    Anyway, on 5.0GHz I needed 1.32V in bios (LLC set to 6) to get it stable in a short term sense. I had it crash out a few threads after 6 hours. What puzzles me is that depending on the P95 task type, the CPU will either stay nice and happy around 65-70C and a calculated HWMonitor CPU wattage of 150W, or ramp up to 200W and 85-90C (ouch), like a switch. It will bounce between the two every 15 minutes or so. The clocks are not throttling, but the VID drops from 1.35V to 1.28V, while the Vcore maintains at 1.36V.

    What's going on here with the temp and wattage switching?
     
  2. CAD4466HK

    CAD4466HK Gawd

    Messages:
    801
    Joined:
    Jul 24, 2008
    You are experiencing an AVX workload in P95 which will increase temps and wattage when it is ran. When those threads crash, it means your OC is not AVX stable at those clocks, but are stable in non-AVX loads. You should have a AVX offset setting in your BIOS, which down clocks your CPU when AVX is ran. You can disable it or run a version without AVX (26.6), if you feel that you will not use AVX in you everyday usage. AVX is starting to be used more and more in games and programs. It has been on Intel CPU's since Sandy Bridge.