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post #14 of (permalink) Old 02-07-2019, 12:37 AM
EarlZ
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Quote: Originally Posted by Falkentyne View Post
Voltage spikes that you are referencing can't be measured by sensors. They require an oscillioscope as these spikes happen in microseconds.
The VR VOUT is simply the base (constant) voltage that is an average from around that time. For smaller loads (like AVX / fma3 disabled), then that's fine and you're right.

The spikes are erratic and very fast. And these spikes get worse when you combine high amps draw with high levels of loadline calibration.
Using Ultra Extreme loadline with small FFT FMA3 (or AVX) prime95 (with lowering bios voltage) to make the same VR VOUT as a higher bios voltage with more vdroop (With LLC=Turbo) would cause a massive drop in stability. Elmor tested this and with small FFT FMA3, he actually needed the same bios voltage with LLC8 (Gigabyte=Ultra Extreme), as with LLC6 (Gigabyte=Turbo) for the same stability, even though the VR VOUT, amps and temps were MUCH MUCH higher (VR VOUT+LLC6=1.078v, VR VOUT+LLC8= VR VOUT 1.141v).

FMA3 small FFT prime95 puts far too much load on the VRM's to allow stability with a flat loadline. But an oscilloscope is needed to see what's going on.

I honestly do not know if they are called voltage spike, I dont have a good terminology for them and I apologize for that. What I do see is for example my load maxes at 1.303v as per VR VOUT, the moment I stop Prime95 It will show me a max reading of 1.367v if they are not called voltage spikes what are they called ?

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Last edited by EarlZ; 02-07-2019 at 12:44 AM.
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