FX-8320 w/ 990FX - throttling issue

[UTL]

My 8320 is installed on an ASRock Fatal1ty 990FX Killer, with Phanteks PH-TC14PE cooler. It's my first overclock, but I've done my reading. In BIOS, I've disabled APM, C1E, C6, Cool 'n' Quiet, AMD Turbo Core, etc., but when I go to stress test the system with Prime95, I see throttling with the multiplier decreasing from 22.5 to 7, so from 4500 MHz to 1400 MHz, every few seconds. Once it starts, it goes back and forth between the two frequencies. Watching the temperature with HWMonitor and AMD Overdrive, it seems to start after the CPU reaches thermal equilibrium, usually around 50-53 degrees (20-17 degree thermal margin according to Overdrive), so no real issue temperature-wise.

I was just getting started with the overclock, so I've tried a few different voltages and seen the same thing. Right now I'm at Vcore = 1.400. I do have the latest version of the BIOS. What other information would be helpful to troubleshoot?

Thanks for the help.

 

[RaDiKaL_]

Which PSU do you have? three factors cause throttling down, overheating, unstable power, bad yielded CPU. Since overheating is not an issue only two possibilities remain, either your PSU is not being able to deliver a stable supply of power (could also be a VRM/Phase regulator issue in mobo but your mobo is known for being solid in that aspect), or you got yourself a low binned CPU which sometimes is simply that.

To find out, monitor your voltages with HWMonitor Pro while stress testing, if the voltage is severely dropping then the PSU is the culprit.

 

[UTL]

CPU-Z shows the voltage drop when the frequency doe, but I have a hard time beliving it's the PSU. I have an EVGA 750 G2, and it's half loaded max. So maybe it's the CPU binning, but what else can I try before I give up? At the very least I should be able to run stable at the turbo frequency, right?

Before I give up, what else can I try?

Thanks, by the way.

 

[Dark Lord of Tech]

Probably the chip , your PSU is first rate.

 

[UTL]

The way it was acting, it looked to me like an APM issue or some other throttling mechanism wasn't actually disabled. So, after yet more searching, I found this thread:

http://forums.tweaktown.com/asrock/46817-asrock-990fx-extreme3-fx-8120-bios-default-cpu-throttling-not-apm.html

This is my problem exactly. I tried the solutions on the last two posts on the thread - the first one did nothing (actually, I had it set to F-stream tuning power profile instead of whatever tool that user had, and F-stream freezes up Windows, even if I just try to adjust fan speed, so that didn't work for me), but the last one actually bore fruit. I had to use another tool to set all p-states to the desired multiplier/voltage, but then it ran! I have stability issues to work out, but it's a workaround.

It looks like the likely culprit might be Cool 'n' Quiet, which I do have disabled in BIOS. Does anyone know why the BIOS settings didn't take?

 

[Nielsg]

The way it was acting, it looked to me like an APM issue or some other throttling mechanism wasn't actually disabled. So, after yet more searching, I found this thread:

http://forums.tweaktown.com/asrock/46817-asrock-990fx-extreme3-fx-8120-bios-default-cpu-throttling-not-apm.html

This is my problem exactly. I tried the solutions on the last two posts on the thread - the first one did nothing (actually, I had it set to F-stream tuning power profile instead of whatever tool that user had, and F-stream freezes up Windows, even if I just try to adjust fan speed, so that didn't work for me), but the last one actually bore fruit. I had to use another tool to set all p-states to the desired multiplier/voltage, but then it ran! I have stability issues to work out, but it's a workaround.

It looks like the likely culprit might be Cool 'n' Quiet, which I do have disabled in BIOS. Does anyone know why the BIOS settings didn't take?

I have the same mobo+cpu and the same problems. It took me a few days to find this answer. Do you use AMDMSRTWEAKER to change the p-states? And how? Is there a command to disable Cool n Quiet? If you can explain the steps you take, I can hopefully run my oc stable

Thanks!

 

[UTL]

I do use AMDMSRTweaker. The way I do it is the method described in this guide:
http://www.overclock.net/t/1499562/undervolting-editing-p-states-for-piledriver-using-amd-mrstweaker-mini-guide
which is about undervolting, but works pretty much the same way for overclocking. Sometimes I have found that if I want something different than what I set in BIOS (live tweaking) the settings don't take unless I set them in AMD Overdrive first, then use AMDMSRTweaker. Basically, set it in BIOS, make sure in Windows it's what you want, then set all p-states the same with the tool.

 

[TorrentialTech]

I have that same issue with my 990FX Killer, anytime I go above 1.4V, it throttles to a multiplier of 7. I suspect it is the VRMs on the board as the VRM heatsink gets extremely hot to the touch. I've moved my top 120mm fan closer to the VRMs and I have placed a 70mm fan from the stock cooler sucking air from the VRMs. It has helped a little but not much.

 

[DYECLOCK]

I had the same problem with my cpu, from reading around turns out if you go anything above the listed cpu speed you will see lots of throttling. When i was using turbo core i would see throttling but less of it compared to a 4400 mhz overclock. The temps with a hyper brand cpu cooler drastically reduced the throttling from the stock fan. If you do decide to stick with the recommended max overclock i would set my multiplier to 20.0 instead of using turbo core.

 

[cricoso]

make sure in Windows it's what you want, then set all p-states the same with the tool.