Problem with CPU stress test!

[Luke]

So i have a Gigabyte 990XA-UD3 and FX-8320 and i sort of tossed overclocking aside because of a problem with this board while using 8 core FX chips. I used to have a phenom X6 1055T overclocked to 3.8Ghz and i didn't have the problem. Anyway what happens is if you open CPU-Z and run prime95 you will see the clock speed dip to 2.9Ghz or so for about 1 second or less and the voltage dips to 1.248. I'm not here looking for suggestions how to fix this because i've tried everything and i don't think it's possible. I've seen people come to the conclusion that it's "throttling" because the northbridge overheats but this happens seconds after you put it under full load so that makes no sense. My temps are also fine.

 

I tried using intel burn test to make sure it wasn't just a problem with prime95 and the same thing happens. The thing is with Cinebench and gaming it doesn't seem to happen so it's not that big of a problem but if you are trying to overclock it makes things pretty much impossible. I managed to get 4.3Ghz stable on stock volts despite the voltage dips so i would love to see what the chip is capable of. The problem is if i stress test with prime95 the or IBT voltage will dip and it can make a theoretically "stable" overclock unstable. 

 

I guess my question would be is there any way to test for stability without putting the CPU under such a high load that it causes this problem? Or if you have any other ideas any help is appreciated. Thanks.

[Luke]

Your voltage is on manual or auto ?

 

Manual.

[Timopomer]

Manual.

its called voltage drooping,if you have LLC you can fix it

[Luke]

its called voltage drooping,if you have LLC you can fix it

 

Isn't vDroop is something different?  Also LLC has no effect on the voltage dip, It just causes it to spike slightly higher than the stock voltage when under load. Thanks though.

[Timopomer]

Isn't vDroop is something different?  Also LLC has no effect on the voltage dip, It just causes it to spike slightly higher than the stock voltage when under load. Thanks though.

well, in my case the cpu drooped with the slightest overclock and llc did fix the droop but resulted in high voltages so im running stock ... maybe enabling it can fix the drooping..play around with it.

 

dunno what setting you will have but i only had llc - auto/enable/disable so i couldnt tweak much.

 

wish you luck tho

[Luke]

well, in my case the cpu drooped with the slightest overclock and llc did fix the droop but resulted in high voltages so im running stock ... maybe enabling it can fix the drooping..play around with it.

 

dunno what setting you will have but i only had llc - auto/enable/disable so i couldnt tweak much.

 

wish you luck tho

 

yea i have "Auto, Normal, Low, Medium, High, Very high, Extreme" or something along those lines. I only tried Auto, Normal and High. All that seems to happen the higher i increase it is a voltage increase when under load =\

[Timopomer]

yea i have "Auto, Normal, Low, Medium, High, Very high, Extreme" or something along those lines. I only tried Auto, Normal and High. All that seems to happen the higher i increase it is a voltage increase when under load =\

but is the voltage not going down anymore?

[Luke]

but is the voltage not going down anymore?

 

It still drops to 1.248. The only difference LLC seems to make is that it spikes to a higher voltage.

[Sintezza]

just bump up the voltage higher.

[Luke]

just bump up the voltage higher.

 

Does nothing. Well it increases the voltage of course but doesn't change the voltage dips and multiplier drops. I've also tried a combination of voltage and LLC but with even the slightest increase in voltage and LLC on low-med settings i uncomfortably high voltage spikes while under load which is the exact opposite of what i'm looking for. 

[Sintezza]

Does nothing. Well it increases the voltage of course but doesn't change the voltage dips and multiplier drops. I've also tried a combination of voltage and LLC but with even the slightest increase in voltage and LLC on low-med settings i uncomfortably high voltage spikes while under load which is the exact opposite of what i'm looking for. 

 

 

Gigabyte had verywell know overheating vrm issues in the past.

Which results in cpu voltage drops..

 

So im affraid it could be your mobo.

[Luke]

Gigabyte had verywell know overheating vrm issues in the past.

Which results in cpu voltage drops..

 

So im affraid it could be your mobo.

 

"I've seen people come to the conclusion that it's "throttling" because the northbridge overheats but this happens seconds after you put it under full load so that makes no sense. My temps are also fine." Quoted from my original post.

 

Thanks for trying to help though.

[-rascal-]

I had a similar issue with my FX-8350. This on an ASUS Crosshair V Formula. The core voltage was too low, and Vdroop was contributing to the issue.

I would rune Prime95 or AIDA64 Stability Test...it would be fine for...45 minutes, 1 hour...and all of a sudden Boom. Voltage tanks, CPU drops down to 2.9GHz.

 

One of the side effects of LLC is saying the voltage to be higher than what is set. This is normal.

As long as the voltage does not spike up too ridiculously (you have it set to 1.4V in the BIOS can it's going up to 1.5V or something) you should be okay.

You need to NOT let the voltage drop lower than what you set...making it unstable. As soon as the voltage drops below the threshold where the CPU is no longer stable, the CPU just collapses down to 2.9GHz.

 

Here is what you can do (or a mix / balance of the them):

• Increase the Core Voltage
• Increase LLC
• Slightly increase the CPU-NB voltage (I believe Gigabyte calls is CPU-PLL in their BIOS. It's the one where the stock voltage is 2.5V). Bring it up to ~2.55V or 2.6V.

From what I know, increasing the CPU-NB / CPU-PLL voltage can assist in counteracting Vdroop.

 

Also:

• Disable APM Master Mode
• Enable HPC (High Performance Computing)

 

Just digging up some of my old threads on the AMD forum...that might come in handy for you:

http://forums.amd.com/game/messageview.cfm?catid=456&threadid=172886&enterthread=y **This on is with the discussion about the 2.9GHz / 2.8GHz drop**

http://forums.amd.com/game/messageview.cfm?catid=446&threadid=172747&STARTPAGE=1&FTVAR_FORUMVIEWTMP=Linear

[Luke]

I had a similar issue with my FX-8350. This on an ASUS Crosshair V Formula. The core voltage was too low, and Vdroop was contributing to the issue.

I would rune Prime95 or AIDA64 Stability Test...it would be fine for...45 minutes, 1 hour...and all of a sudden Boom. Voltage tanks, CPU drops down to 2.9GHz.

 

One of the side effects of LLC is saying the voltage to be higher than what is set. This is normal.

As long as the voltage does not spike up too ridiculously (you have it set to 1.4V in the BIOS can it's going up to 1.5V or something) you should be okay.

You need to NOT let the voltage drop lower than what you set...making it unstable. As soon as the voltage drops below the threshold where the CPU is no longer stable, the CPU just collapses down to 2.9GHz.

 

Here is what you can do (or a mix / balance of the them):

• Increase the Core Voltage
• Increase LLC
• Slightly increase the CPU-NB voltage (I believe Gigabyte calls is CPU-PLL in their BIOS. It's the one where the stock voltage is 2.5V). Bring it up to ~2.55V or 2.6V.

From what I know, increasing the CPU-NB / CPU-PLL voltage can assist in counteracting Vdroop.

 

Also:

• Disable APM Master Mode
• Enable HPC (High Performance Computing)

 

Just digging up some of my old threads on the AMD forum...that might come in handy for you:

http://forums.amd.com/game/messageview.cfm?catid=456&threadid=172886&enterthread=y **This on is with the discussion about the 2.9GHz / 2.8GHz drop**

http://forums.amd.com/game/messageview.cfm?catid=446&threadid=172747&STARTPAGE=1&FTVAR_FORUMVIEWTMP=Linear

 

Yea holy shit i actually just figured it out before you left that comment. APM Master mode is what was fucking me over. It seems that when Core Performance Boost is turned off but APM Master mode is left on things go a bit screwy. Thanks a lot for taking your time to write that comment it's very helpful and will really help anyone else with the same problem!

[-rascal-]

Yea holy shit i actually just figured it out before you left that comment. APM Master mode is what was fucking me over. It seems that when Core Performance Boost is turned off but APM Master mode is left on things go a bit screwy. Thanks a lot for taking your time to write that comment it's very helpful and will really help anyone else with the same problem!

 

Cool, cool.

:lol:

[Luke]

Cool, cool.

:lol:

 

Oh yea. Pretty stoked seeing a solid 4026.27Mhz in CPU-Z without that dreaded 2.9Ghz core speed or voltage drop. The voltage was only fluctuating between 1.344-1.367 but unfortunately i quickly noticed my temps got a bit crazy so i shut it down.

[Timopomer]

I had a similar issue with my FX-8350. This on an ASUS Crosshair V Formula. The core voltage was too low, and Vdroop was contributing to the issue.

I would rune Prime95 or AIDA64 Stability Test...it would be fine for...45 minutes, 1 hour...and all of a sudden Boom. Voltage tanks, CPU drops down to 2.9GHz.

 

One of the side effects of LLC is saying the voltage to be higher than what is set. This is normal.

As long as the voltage does not spike up too ridiculously (you have it set to 1.4V in the BIOS can it's going up to 1.5V or something) you should be okay.

You need to NOT let the voltage drop lower than what you set...making it unstable. As soon as the voltage drops below the threshold where the CPU is no longer stable, the CPU just collapses down to 2.9GHz.

 

Here is what you can do (or a mix / balance of the them):

• Increase the Core Voltage
• Increase LLC
• Slightly increase the CPU-NB voltage (I believe Gigabyte calls is CPU-PLL in their BIOS. It's the one where the stock voltage is 2.5V). Bring it up to ~2.55V or 2.6V.

From what I know, increasing the CPU-NB / CPU-PLL voltage can assist in counteracting Vdroop.

 

Also:

• Disable APM Master Mode
• Enable HPC (High Performance Computing)

 

Just digging up some of my old threads on the AMD forum...that might come in handy for you:

http://forums.amd.com/game/messageview.cfm?catid=456&threadid=172886&enterthread=y **This on is with the discussion about the 2.9GHz / 2.8GHz drop**

http://forums.amd.com/game/messageview.cfm?catid=446&threadid=172747&STARTPAGE=1&FTVAR_FORUMVIEWTMP=Linear

are you serious? what does APM even do? if thats my problem i might try to OC again

[-rascal-]

are you serious? what does APM even do? if thats my problem i might try to OC again

APM = Application Power Management.

It works to KEEP the CPU within the 125W TDP limit.

So will raise / lower the voltage depending in the usage / programs running.

If you're overclocking, you are most likely going beyond the 125W TDP...so the APM is fighting AGAINST your overclocking.

[Timopomer]

APM = Application Power Management.

It works to KEEP the CPU within the 125W TDP limit.

So will raise / lower the voltage depending in the usage / programs running.

If you're overclocking, you are most likely going beyond the 125W TDP...so the APM is fighting AGAINST your overclocking.

wow,this might have been the problem all along.

 

so what do you suggest to stop the voltage from going down?

 

should i use llc or not? i cant set a percentage on my mobo its or enabled or auto or disabled