3900x weird behavior

Randall Stephens

[H]ard|Gawd
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Mar 3, 2017
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Finally got around to running some tests on the new machine and noticed some weird behavior. No PBO enabled in the BIOS, never overclocked. Ryzen balanced power plan Win 10. During a blender workload one of the cores, Core 11, starts off with all the others, then falls down to well below base clocks. Here's the Ryzen master screen. Anybody seen this before?
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With no PBO and your PPT, TDC and EDC set to the AMD Default you see you are hitting 100% PPT there and almost 100% TDC and EDC. Once you hit 100% of any of those, especially PPT the chip will slow down cores to keep levels down to 100% and core 11 looks to be the one main one that gets hit. If you enable PBO those 3 limits raise to the motherboard limits, which the chip would never need or hit and then your chip will only be limited by temps, heat. This is what P95 looks like on my 3900X with the 1usmus power plan and PBO enabled, along with the EDC bug tweak which as you can see does some extra stuff on the EDC limit.
 

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With no PBO and your PPT, TDC and EDC set to the AMD Default you see you are hitting 100% PPT there and almost 100% TDC and EDC. Once you hit 100% of any of those, especially PPT the chip will slow down cores to keep levels down to 100% and core 11 looks to be the one main one that gets hit. If you enable PBO those 3 limits raise to the motherboard limits, which the chip would never need or hit and then your chip will only be limited by temps, heat. This is what P95 looks like on my 3900X with the 1usmus power plan and PBO enabled, along with the EDC bug tweak which as you can see does some extra stuff on the EDC limit.

thanks, I’ll take a look tonight.
 
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