New build not stable at any core speed,need help

[Bilbo Swaggins]

Hi guys new member here. Just finished a new build over the weekend and got it up and running no problems so first things first here are the parts:

AMD FX 8350 black edition
Asrock 990FX Killer mobo
Corsair vengeance pro 2x4gb @ 1600MHz
Corsair CX750M PSU
Corsair H55 hydro series cpu cooler
SAPPHIRE r9 270x toxic boost edition
NZXT Phantom 240 mid tower

Ok so my problem is,after installing cpu-z,hwmonitor and the likes I decided I'd run prime95 to test stability at stock speeds before trying any OCing at all and I'm having some weird results to be honest.

The system passed prime95 for over 20 minutes but as I came back and started watching with cpu-z I noticed the core voltage and core speeds dropping drastically,I'm talking from 4.00ghz down to 1.4ghz and voltage from i think it's around 1.3ish if i remember but drops down to 0.800 levels which seems completely absurd to me. This all happens really quickly and then continues on and on. So far I haven't had time to do much gaming on it yet but it seems to play fine,played bf4 for almost 3 hours straight last night,other than that not much use yet.

Now at that point I also checked temps and it seems that as the core temp reaches over 55C (I'm from Australia just so all you who read this don't freak out at that number) is when it'll drop but it's not consistent enough for me to go saying it's a temp problem but it's definitely near the top of the list I'd guess.

So yeah,after trying all afternoon to find a solution my only choice was to actually make my own thread as I still haven't found a problem exactly like mine and I'm all out of hope for now. As I said it's a completely new build so it's a little disheartening to say the least but I'm hoping someone a lot more knowledgable than me can help me out.

Sorry for the long post but I'm off to bed for the night so won't be able to reply until after work tomorrow so just wanted to get all the main problems out there in the hopes that we'll find a solution. Thanks and hope to get some responses soon

 

[Unolocogringo]

Check your cooler install.
The downclocking in prime 95 is from overheating.
The processor will downclock and lower voltages to keep it from overheating.
Prime 95 will max all cores. Making the processor hotter than any game or general usage.

 

[Bilbo Swaggins]

Ah ok thanks I'll try that first thing tomorrow after work. So do you think it may be installed too loose perhaps?

 

[Bilbo Swaggins]

Ok so I decided to check the installation of the cooler and it was a little loose for sure. After tightening it up,i'm currently running prime 95 now with hwmonitor and cpu-z and i'm still getting the drops from 1.288v down to 0.880,and cpu drops from stock to 1399.9MHz! seemingly every other second it will do this.

The only thing that has changed are the temps which are lower now so that's a plus but still no luck with the core speed/voltage problem. I should mention it happens fairly quick too,around 3-5 minutes of running prime95

 

[Bilbo Swaggins]

One last thing to note is that the system hasn't crashed or anything through all of this,it still continues to run,no BSOD or shutdown or anything. Just thought I'd share that piece of info as well for anyone that has any more ideas

 

[Cristi72]

Hello,

Please go into UEFI menu, OC Tweaker and disable "AMD Application Power Management". This feature tries to keep the TDP as low as possible in case of overclocking.

 

[Bilbo Swaggins]

Hi,thanks for the input but unfortunately I have already disabled any and all power saving features in the uefi and in windows itself :/

 

[Bilbo Swaggins]

Guys I should mention that this is running at STOCK speeds so surely it should be able to at least handle that am I right? I did reseat the cooler last night as I hadn't tightened it on enough so I'll see how it goes this afternoon after it has been sitting for the day. I'm a bit of a novice so I'm not really sure where to go from here

 

[Cristi72]

Hi,thanks for the input but unfortunately I have already disabled any and all power saving features in the uefi and in windows itself :/

From UEFI, disable Cool&Quiet, C1E state, CPU Fan Control.
Download and install the application "AMD Overdrive": http://www.amd.com/en-us/markets/game/downloads/overdrive, it will give you the possibility to disable the APM (Application Power Management) and Turbo Core directly from Windows (maybe they got reactivated when entering Windows).

If still no result, try lowering the CPU frequency (use the multiplier, go down one step at a time), then the voltage (go down in 0.025V steps). If still the same, maybe you have a bad CPU or there is something wrong with the motherboard.

Did you checked the temperature of the chipset and VRM radiators? Try to mount a fan right above the CPU, for properly cool the chipset and the VRM (usually they are cooled by the airflow from the CPU stock cooler, but because you are using a liquid cooler there is no airflow anymore in that area).

The motherboard have the latest BIOS version installed?

 

[Bilbo Swaggins]

Yeah sorry as I said in the previous post I have already disabled all power saving/throttling features in uefi and in windows itself. I'm beginning to think it may be an overheating issue but I haven't ruled out other possibilities either. So maybe underclocking for a test might be the way to go? seeing as it should run at lower temps I assume and determine if my current config isn't handling the heat at the stock speed? If that is the case it'svery disappointing indeed

 

[Cristi72]

Yeah sorry as I said in the previous post I have already disabled all power saving/throttling features in uefi and in windows itself. I'm beginning to think it may be an overheating issue but I haven't ruled out other possibilities either. So maybe underclocking for a test might be the way to go? seeing as it should run at lower temps I assume and determine if my current config isn't handling the heat at the stock speed? If that is the case it'svery disappointing indeed

A CPU temperature under 60C under full load is normal, especially for a power hog such FX8350.

Check the chipset and the VRM temperature, they are prone to overheating because the liquid cooling system cannot assure the necessary airflow. For the best airflow, the H55 should be mounted on the back of the case and at least an additional fan on top of the case, all in exhaust configuration (taking out the hot air from the case). Also, you should have two fans mounted in the front bay of the case as intakes for the cold air.

Please post a picture with your setup, especially the CPU area.

 

[Bilbo Swaggins]

OK guys so here's what I've done this afternoon. I monitored the temps when I got home in hwmonitor and they still seemed too high for running idle,the socket temp was what was more concerning (can't remember exactly what it was now sorry) so i decided to take the fan off my heatsink I got with the cpu and placed it behind the motherboard blowing air onto the cpu socket.

since then I haven't tested prime95 yet but I can definitely confirm that all temps are now considerably lower after doing that and last night adjusting the cpu cooler installation which definitely wasn't tightened up near enough.

Apart from being a bit loud it seems to be running alright temp wise now but I'll leave this open until I test prime95 later on and see if it holds without the drops for at least 10-15 minutes (only took 3-4 minutes to start dropping yesterday running p95 so should get a clear idea quickly)

Thanks for all the inout so far guys I appreciate it.

As for the h55 installation,I actually placed it on the first of the fan slots (closest to back of the case) at the top of the case running as exhaust as I'm pretty sure there would have been s clearance problem with the heatsink on the mosfets right near it. I have seen it configured that way before and I'm fine with having it there as it is still doing the same job running exhaust

 

[Bilbo Swaggins]

Ok so I finally got around to running prime95 after placing a fan behind the cpu socket are on the back of the motherboard and as I suspected it solved the issue of the extreme voltage and core speed drops I was experiencing while running it earlier in the week.

Now for one last thing I need advice on as I'm unsure about it. The core voltage under load was pretty much a steady 1.224 V running at 4099 mhz core speed so this leads to my question of what should the v core be set at? right now in the bios it says 1.3250 and had an offset of +0.50 mv but yet it's running so low under that so do I need to lower the voltage or leave it as is?

I'm very unsure of this one so if anybody could answer for me I'd really appreciate it thanks. I'd post a photo of hwmonitor and cpu-z running alongside p95 but I don't know how to post them here :/

 

[Unolocogringo]

If it is stable at those voltages I would leave it alone.
It is normal for voltage to be lower under load. It is called V droop.
If it is unstable you can enable LLC or Line Load Calibration in the bios.
It will automatically increase input voltage when loaded to keep a constant voltage at the processor. Some chips need this for stability and others do not.
For best temps and power efficiency you can lower voltage and test with Prime 95 to find the lowest stable voltage your chip will run at. But this can be a time consuming process. As you would need to run Prime 95 12-24 hours at each step to insure complete stability.