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Windows messing with CPU Vcore?

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#1
I was overclocking my Bulldozer and I hit a wall very quickly. No matter if I increased my Vcore over the default a little or a lot, it would fail the very same way.
Then I noticed a strange thing:
Whenever my CPU was under load the Vcore would drop, the more load on more cores it had, the more it would drop. With 2 Cores on full load drops by ~ 0.05 V; With 4 Cores - by 0.09 to 0.12 V (would start making occasional calculation errors); With all 8 cores on full load at once, I would see the Vcore to drop to <1.2 V almost in an instant. That is way below the voltage needed to run at such clock speeds so my computer would freeze in a second or two.

I thought it my be my PSU at first. I could see the PSU was running on less than third it's maximum capacity, thus barely loaded. And that PSU is quite new. So unlikely a PSU problem.
It seemed is as if something would try to enforce the TDP in any means available. And since I had all the power saving features turned off, it suspect it goes after my Vcore to to so.

Now it get to the weird part:
I was doing it on Windows. Almost solely because I wanted to use CPU-Z.
Now, I went back to Linux, where I usually "live". I can see the clockspeed of my CPU there, but can't monitor the Vcore. I kept the same clocks and voltages. I then went on to stress my CPU there. I was surprised - it ran rock-solid with all of my cores on full load. As if the CPU would get the voltage I intended.But running rock solid on Linux with what would would crash Windows in mere seconds? That is really odd.

I suspect it could be that Windows or it's chipset drivers are enforcing the TDP.
I also suspect one other thing: I am using the latest BIOS. And a couple of BIOS versions back, the changelog says "Add VRM MOS protection". Maybe the BIOS is F***ing with me by enforcing that TDP? I suppose Windows honor what BIOS decides, while the Linux kernel is known to sometimes not give a f*** over what BIOS says when it wants / knows better and overriding it's functions (thus explaining not enforcing this presumed limit).

Does that mean "Windows be bad for 'dem bulldozers & Piledrivers"? Since A BIOS update to support PD CPUs probably wont remove this.

Expert advice on what to do in such situation would be great.
 
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#2
There are some settings in the BIOS/UEFI that appear to "cause massive vdroop" like symptoms from my experience with my ASRock 990FX Extreme4. Let me take a look real quick, but I bet one of them is called "APM."

EDIT: Settings to try disabling and seeing which ones affect you (I'm not going to mess with mine as I don't have time to test):

Core C6 state
Enhanced Halt State (C1E)
Cool 'n Quiet (not sure if that causes the throttling as well. All I know is that BD works a lot differently than Phenom).
AMD Application Power Management
 
Joined
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Kaunas, Lithuania
System Name Eternal WIP ][ HP ProLiant server blade
Processor AMD FX-8320 @ 4.4/4.1 GHz ][ 2x Intel Xeon L5520 @ 2.27GHz
Motherboard Asus Crosshair V Formula-Z ][ -
Cooling Corsair H55 ][ Stock
Memory 2x4GB Kingston HyperX Genesis @ 1866MHz ][ 4x4 GiB Hynix @ 1333 MHz; ECC on
Video Card(s) 2x MSI GeForce GTX 770 DirectCU II OC ][ None
Storage 1TB WD Black + 1.5TB WD Green + 750GB Samsung + 64GB OCZ Agility 4 ][ 3x 1 TB Hitachi
Display(s) Asus VG278H + Asus VH226H ][ None
Case Antec Nine Hundred ][ it's a server blade, lol
Audio Device(s) Supreme FX II (Integrated); Using optical S/PDIF output ][ none
Power Supply Corsair AX1200i ][ [stock]
Software Gentoo Linux ][ Linux Mint 16
Benchmark Scores 65970 BogoMIPS. Ha. Ha. Ha. >=|
#3
Thanks for replying
But as I wrote: I have all the power saving features off. In other words - all those are turned off.

P.S. *sigh* I wish it was something as simple as that. If I could set something in my BIOS to fix this, I would have done it. Yet I am already out of things that mess with clocks/voltages to disable. I hit a wall at trying to solve this myself =|

EDIT:
P.P.S. As soon as I get my UPS up, I will try to downgrade my BIOS to see if the problem is in that update. But, if this shows that to be the case, I can't use this "solution" if I want to upgrade to Piledriver. :shadedshu

P.P.P.S. @Jstn7477 Seriously! :p
 
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System Name Awesomesauce 4.3 | Laptop (MSI GE72VR 6RF Apache Pro-023)
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Motherboard Gigabyte GA-X99-UD5 WiFi LGA2011-v3| Stock
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Memory G.Skill RJ-4 16GB DDR4-2666 CL15 quad channel | 12GB DDR4-2133
Video Card(s) ASUS ROG Strix A8G Gaming GTX 1080 @ 2075/1368 boost | NVIDIA GTX 1060 6GB +200/+500 + Intel 530
Storage Samsung 840 EVO 500GB + Seagate 3TB 7200RPM + others | Kingston 256GB M.2 SATA + 1TB 7200RPM
Display(s) Acer G257HU 1440p 60Hz AH-IPS 4ms | 17.3" 1920*1080 60Hz wide angle TN notebook panel
Case Fractal Design Define XL R2 | MSI
Audio Device(s) Creative Sound Blaster Z | Realtek with quad stereo speakers and subwoofer
Power Supply Corsair HX850i Platinum | 19.5v 180w Delta brick
Software Windows 10 Pro x64 | Windows 10 Home x64
Benchmark Scores GTX 1080 please?
#4
Yeah, I was extremely irritated with my FX-8150 and overclocking for a while. I had to set 1.45v in the BIOS to do 4.2GHz and it was ridiculous because it looked like my board had horrific vdroop as it would go down to 1.32v! Once I disabled those settings, I now set 1.275v in the BIOS and the voltage doesn't even budge.

One more thing, did you disable Turbo Core as well? I disable turbo boost/turbo core on every machine I own because I do distributed computing and the processor will just run all cores at the lowest frequency anyway. Turning off turbo for me assures me that one core won't go to 4 billion GHz and crash the system. :)
 
Joined
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Messages
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Location
Kaunas, Lithuania
System Name Eternal WIP ][ HP ProLiant server blade
Processor AMD FX-8320 @ 4.4/4.1 GHz ][ 2x Intel Xeon L5520 @ 2.27GHz
Motherboard Asus Crosshair V Formula-Z ][ -
Cooling Corsair H55 ][ Stock
Memory 2x4GB Kingston HyperX Genesis @ 1866MHz ][ 4x4 GiB Hynix @ 1333 MHz; ECC on
Video Card(s) 2x MSI GeForce GTX 770 DirectCU II OC ][ None
Storage 1TB WD Black + 1.5TB WD Green + 750GB Samsung + 64GB OCZ Agility 4 ][ 3x 1 TB Hitachi
Display(s) Asus VG278H + Asus VH226H ][ None
Case Antec Nine Hundred ][ it's a server blade, lol
Audio Device(s) Supreme FX II (Integrated); Using optical S/PDIF output ][ none
Power Supply Corsair AX1200i ][ [stock]
Software Gentoo Linux ][ Linux Mint 16
Benchmark Scores 65970 BogoMIPS. Ha. Ha. Ha. >=|
#5
One more thing, did you disable Turbo Core as well? I disable turbo boost/turbo core on every machine I own because I do distributed computing and the processor will just run all cores at the lowest frequency anyway.
Yes, I had [and still have] it disabled.
No use in keeping it on - as it won't work when AMD APM is disabled anyways. For me, at least. ;)