CPU-Vcore Voltage drop and lag

Jopa · Mar 9, 2016

Hello guys i have a question about my FX-8350. Is it normal that my CPU-Vcore Voltage drop from 1,4V to 0.8V when i am rendering or streaming? My pc lag ( frame rate drop to 10-12 ) even though my temps are normal? (sorry for bad english)

PC specs:
ASRock 970 Pro3 R2.0
AMD FX-8350@4.5 Ghz
Cooler Master Seidon 120V
Cooler Master Silencio 452
MSI GeForce GTX 750Ti

https://youtu.be/pW3GazIFwBU

**EDIT 1** control panel power profile is set to performance
**EDIT 2** cool N quiet disabled. And i can't find Line load calibration in bios.

Darkbreeze :

techgeek · Mar 9, 2016

With performance mode set, I wouldn't think that should happen. You could try to go into your BIOS and turn off AMD Cool 'n Quiet and see if that eliminates the problem.

It's odd that from your video it looks like your clockspeed stays at 4500MHz even when Vcore drops.

Still couldn't hurt to try turning off Cool 'n Quiet to see it if helps.

chris987 · Mar 9, 2016

most probably vrm throttling. your mobo isnt good for 125w tdp 8core cpu. i suggest you get a better mobo. what psu do you have.?

Jopa · Mar 9, 2016

Just edited my post. I have LC POWER LC8650II V2.3 650w modular PSU

chris987 · Mar 9, 2016

your psu isnt good either but should suffice for such system with no supplementary power needed from the gpu. there are know problems regarding your mobo and the 8core cpu.

Sakkura · Mar 9, 2016

Most LC Power units are very low quality. It might be causing the problem. I would recommend upgrading to a higher quality unit regardless.

Jopa · Mar 9, 2016

I don't think it's psu since i had corsair and it was the same problem.

techgeek · Mar 9, 2016

I don't think LLC will fix that, I've never seen .6V line drop before.

If you had power supply issues, or VRM's were acting up, your system would restart, BSOD, crash etc. VRM's don't throttle, CPU's throttle. If a VRM is having problems, Vcore would drop and your system would do one of the above.

techgeek · Mar 9, 2016

Can you go into your Advanced Settings under your power plan and tell me what your minimum and maximum processor states are under Processor Power Management are?

chris987 · Mar 9, 2016

techgeek :

usually there is also protection in the mobos vrm. thats what happenning to weak vrm , drops cpu core voltage, clock. if with turbo core off still has the same result then it just cant handle the cpu.

techgeek · Mar 9, 2016

If Vcore drops without a corresponding drop in clockspeed while under load, the computer will shut off or restart. The CPU can't run at 4.5GHz at .8V while under load.

Jopa · Mar 9, 2016

techgeek :

I dont know what that is. Do you want a pic?

chris987 · Mar 9, 2016

techgeek :

i agree but that maybe a false speed / voltage reading since there is a substantial drop in performance, with no effect on the cpu temps.! usualy there is also a core clock drop though. anyway thats a mobo insufficient for 125w tdp 8core cpu.

techgeek · Mar 9, 2016

@ OP, just noticed that you have an overclock. Have you tried to eliminate the overclock to see if the behavior goes away?

Jopa · Mar 9, 2016

techgeek :

Yes i have tried. It's same behavior.

Darkbreeze · Mar 10, 2016

techgeek :

This is exactly what I said in his first inquiry, in the Piledriver Mega-thread, but I didn't know the motherboard model at that time. This is 100% VRM throttling in all probability.

Disable the overclock, first. Then, set the multiplier to assign a 3.5Ghz base clock speed. Disable turbo boost. Disable cool and quiet. Change you control panel power profile to performance. Then see if it still does it.

In my experience, the 970 Pro3 is not capable of handling 8 core FX processors. VRM throttling almost always occurs because the power phase and thermals are not up to the task. I'd highly suggest that:

1. You put the stock cooler back on for now, because with liquid cooling you are not getting ANY residual airflow in the area of the VRMs like you would with the stock "top down" cooler than blows down onto the heatsink and motherboard.

2. You get a better motherboard. I always recommend getting one of the following models if you're going to overclock an FX 8 core processor.

Extreme6 (Termed as 990X chipset board on some sites)
Extreme9
Fatal1ty 990FX Professional
Crosshair V Formula-Z
Sabertooth 990FX R2.0
GA-99FXA-UD5
MSI GD80V2
M5A99FX PRO R2.0
GA-99FXA-UD3
MSI GD65V2
990FX Killer
Extreme4
M5A99X EVO (R2.0 as well)
GA-990XA-UD3
990XA-GD55
GA-970A-UD3P
M5A97 or EVO or PRO (R.2 as well)
GA-970A-UD3
970 GAMING
970 Performance

3. Get a high end air cooler OR, get a bigger liquid cooler and plan to have as much case cooling via case fans as you have locations to install fans in. If you use liquid cooling when overclocking FX 8 or 9 series chips, you will be likely to have VRM throttling on even good boards because you eliminate the airflow in the area of the motherboard voltage regulator modules.

Another option is to rig/fabricate a VRM cooling fan, by creating some kind of bracket or mounting system that allows you to install a fan directly over the VRMs to provide cooling so they do not heat up and throttle. If you Google VRM cooling fan modifications you can find a variety of ideas on how to do this. Even with a very good tower cooler, you do not have downward airflow so some amount of VRM throttling can still occur under demanding conditions, but is less prevalent than with a water cooler.

Also, that little 120mm liquid cooler has less cooling capability than any half decent tower cooler. I'd either opt for a 240 or 280mm liquid cooler, or just ditch it altogether and get a decent air cooler. In the meantime, using the stock fan should allow you to at least use the system at it's default settings without having to worry as much about the VRMs overheating.

chris987 · Mar 10, 2016

save yourself from trouble and frustration and get a proper mobo. my suggestion the new remake of the gigabyte UD line . your aio is still capable of moderate o/c.

Price breakdown by merchant: http://pcpartpicker.com/p/TkGB3C/by_merchant/
Motherboard: Gigabyte GA-990FXA-UD3 R5 ATX AM3+ Motherboard ($92.98 @ Newegg)
Total: $92.98
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-03-10 04:17 EST-0500

Darkbreeze · Mar 10, 2016

Yes, for the price that board is exceptional. So is the 970 series ASRock 970 Performance, which has been shown to be at least "approved" for running FX-9xxx series chips, so it's thermals and power phase are very good. It's the same price at 92.00 though so IMO the 990FX-UD3 is a better option, at least if you want the option for dual cards. The 970 performance supports limited crossfire and no SLI.

Jopa · Mar 12, 2016

Hello guys, thx for all your help. This is what i did hope it will work.

EDIT: SEEMS LIKE IT'S WORKING !!! THX GUYS!!!

Temps now: http://imgur.com/g8L5CKB

Darkbreeze · Mar 12, 2016

That lower fan next the the water block looks like it's totally packed with dust. Am I seeing that right? You need to get that thing blown out. That might be half your problem right there.

Jopa · Mar 12, 2016

I don't have problem anymore. But yea i know.

Darkbreeze · Mar 12, 2016

Well, you might have even less of a problem, or no problem at all, or might not have had a problem in the first place, if you took a 3 dollar can of compressed air and blew that crap out. Anyhow, glad you're up and running. I'd fix that though before the caps under that heatsink decide to fail and renders your board useless.

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