Prime95+FX-6300+Large Vcore drops

I've been trying to overclock my processor past 4.3GHz but the CPU voltage plummets from 4.23v down to 1.28~1.302 every time I run small FFT in prime95. Even with 4.3GHz it'll slam down to 1.28v when I have the voltage set to 1.45 when prime95 small FTT testing but it'll pass 10 minutes of it and last 2 hours OCCT. Motherboard is a 970a-UD3 from gigabyte and the above voltages are set using Extreme LLC with C1E/6, CnQ, and APM turned off. Any suggestions?
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  1. Is it a PSU, mobo, or CPU problem? Will VDDA help stop this? Is PLL synonymous with VDDA? I'm out of ideas. I ran large data set on OCCT and the voltage plummeted too. When the program stops the voltage doesn't return to normal. I'm using the F7 bios and corsair 650w PSU
  2. How old is psu? System specs? Gpu? Heavy other loads like lighting or fans? If you have your power management turned off, then likely psu or mobo vrm issue. Speaking of which, does air easily and cleanly get to your vrm heatsinks?
  3. Motherboard: GIGABYTE GA-970A-UD3----Video card: XFX Double D FX-787A-CDFC
    Radeon HD 7870 GHz Edition 2GB----CPU: AMD FX-6300 Vishera 3.5GHz (4.1GHz Turbo) Socket AM3+ 95W Six-Core Desktop Processor FD6300WMHKBOX ----RAM: CORSAIR Vengeance 8GB (2 x 4GB) 240-Pin DDR3 SDRAM
    DDR3 1600 (PC3 12800) Desktop Memory Model CMZ8GX3M2A1600C9B----HDD: Western
    Digital WD Black WD1002FAEX 1TB 7200 RPM SATA 6.0Gb/s----PSU: CORSAIR
    Enthusiast Series TX650

    All these parts were assembled in February 2013, the rig is new. C1E, C6E, APM, and CnQ are off. 120mm Fan on the back of the case is blowing over the VRM and a CM212+ is blowing air up to a 140mm fan blowing out of my case.
  4. When this happens can you use a program like hwmonitor to get vrm temps? Trying to rule out.

    Other thought, did you OC in bios or using windows interfaced software?

    Really leaning on psu possibility. Just trying to rule out mobo
  5. I'm not sure what tmpin # VRM is in HWmonitor and I only overclock through bios
  6. There will be usually 4-5 sensor temp values well above cpu values - good indicator of vrm temp sensor
  7. Tmpin2 value is 12C above the CPU temp, I remember someone telling me VRM temps will always be 10C above CPU so that may be it. Vcore was set to 1.42 but as soon as I launched FFT small from prime 95 they haven't budged from 1.328v and the CPU is OC at 4.3. The CPU is 46C and VRM (if tmpin2 is VRM) is at 57C. FFT released at 10 min and now the vcore is at 1.280 to 1.296
  8. There is still a green power demon at work here. Something EPS/APM/speedstep etc is still active. Ill have to do some checking on your board/bios unless someone beats me to it

    Meantime, any chance you can get a psu to swap temporarily to rule that out?
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