Is my CPU Unstable?

[Novalife818]

Hello,

 

I recently setup my new gaming PC and have a few questions

 

1.I have an AMD FX-8350 and when I pull up Core Temp or HWMonitor I get numbers that are all over the place. These numbers are not high sub 40C but they are not stable. As I open programs the numbers begin to rise (As Expected) but they stabilize. Is this normal for idle temperatures to be jumpy?  

 

2. I downloaded Prime95 and ran a small 10 minute test. While running this test I had Task Manager open to monitor the CPU Usage.... All is going well but then I get a dip in performance. The program will report 100% for about 20 seconds and then drop to about 30% for 5-10 seconds then repeat. I thought this might have been the program turning off and then starting again. Is this normal?

[RamboOC]

Your cpu might be throttling for some reason, eg overheating cpu or vrm's

[FizzyFantom]

1. AMD FX CPUs don't have any actual temperature sensors on the chip, so the temperature is calculated using the power draw and other information. This is usually very accurate over 50 degrees C, but can be less so around 30-40 where it might be idling, meaning it could be jumpy.

2. The Prime95 stress test is supposed to use 100% of the CPU throughout the test. The CPU may be thermally throttling, but it could also be software or MB related. Is there any other useful information you could provide such as your cooling, your MB or other system specs?

[Novalife818]

@RamboOC 

I just set this build up with all new parts and an aftermarket cooler. Also I haven't overclocked or anything.

Do you have any suggestions on what I should do?

[Needalight]

You do realize that Prime95 is a stress test and its going to put your PC on 100% LOAD. Every single core...You should keep it running longer..and your temps look fine for a 10 minute test..except for that 99c I see on there, that seems to be very inaccurate. 

[Novalife818]

@FizzyFantom

 

-AMD FX-8350

-MSI 970A-G43 Motherboard

-Cooler Master T4 Cooler 

-Gigabyte R9 280X OC Edition

-8GB of Hyper Hyper 1600 Ram

 

Would the above help at all?

Also, what would you do if you were in my situation?

[Novalife818]

@Needalight

 

Yes, I do realize that Priem95 will put all my cores to work.... My concern is the fact that in Task Manger I will have a "Stable 100% reading" and then it will dip to around 30% for a few seconds then pop back up to 100% again. I have done no overclocking and just want my PC to run like it is supposed to...

[Needalight]

@Needalight

 

Yes, I do realize that Priem95 will put all my cores to work.... My concern is the fact that in Task Manger I will have a "Stable 100% reading" and then it will dip to around 30% for a few seconds then pop back up to 100% again. I have done no overclocking and just want my PC to run like it is supposed to...

 

 

Thats because Prime 95 does the test once and then it starts again, and then it repeats until you stop it. 

[FizzyFantom]

@FizzyFantom

 

-AMD FX-8350

-MSI 970A-G43 Motherboard

-Cooler Master T4 Cooler 

-Gigabyte R9 280X OC Edition

-8GB of Hyper Hyper 1600 Ram

 

Would the above help at all?

Also, what would you do if you were in my situation?

Thanks for some more info.

My friend had a defective FX 8350. I'm running a system with an 8320 and the same MB, so we switched the CPUs to test his PC. I would assume this isn't an option for you, but we also underclocked the CPU to check it out and at 3.5GHz it worked for much longer (overheating indstead of Prime95 producing an error). You could try underclocking it and seeing if it runs correctly at lower clock speeds (which might indicate a faulty CPU)

[Novalife818]

@Needalight 

So basically what you are telling me is that it is just the program starting its test again? 

Does your system do this?

Should I be worried?

Thanks for the help by the way.

[Needalight]

@Needalight 

So basically what you are telling me is that it is just the program starting its test again? 

Does your system do this?

Should I be worried?

Thanks for the help by the way.

 

 

That only usually happens at the start. You need to leave it running for a while before you can conclude anything. 10 minutes is nothing..Most people recommend 10-24 Hours. 

[Novalife818]

@FizzyFantom

 

Thanks for all the help. I still have a couple more questions.

-If something were wrong with my CPU wouldn't I receive an Error message?

-What did your friend end up doing with his defective 8350?

[FizzyFantom]

@Needalight 

So basically what you are telling me is that it is just the program starting its test again? 

Does your system do this?

Should I be worried?

Thanks for the help by the way.

The program does not start the test again while running, so you shouldn't be seeing any CPU usage drop during a stress test. I have never seen any systems CPU usage drop during a Prime95 test, so this is rather strange behaviour. It may not be your CPU that is defective and it's very possible that nothing is defective. I have seen very strange behaviour from PCs with loose RAM chips (look up "chip creep" for more info on that). I've fixed some very odd stuff by reseating RAM, GPUs, MB batteries and other things, so give that a try first.

[FizzyFantom]

@FizzyFantom

 

Thanks for all the help. I still have a couple more questions.

-If something were wrong with my CPU wouldn't I receive an Error message?

-What did your friend end up doing with his defective 8350?

If your CPU is defective Prime95 will give back a math error on one or more of the cores, or the system will lock up and crash completely.

My friend bought a new 8350 and gave the old one to me (it seems stable at 3.2GHz and I'm calling it an 8250 )

[Novalife818]

@Needalight

 

Alright last question before I start up my test again...

Does Prime95 tell you if there is a problem? like does it pop up with a notification?

Also should I turn on "Round Off Checking? What does that do?

What setting should I put Prime95 on for my Test?

[Novalife818]

@FizzyFantom 

That's pretty nice of your friend to do that. Question! Would this math error code pop up on my screen or would I have to look for it? Basically what I'm asking is where would it be located?

And how long should I run Prime95?

 

Thanks for all the help. I really appreciate it.

[Novalife818]

@FizzyFantom

Also, should I turn on "Round Off Checking? What does that do? Its under the Advanced setting toward the top.

What setting should I put Prime95 on for my Test?

[FizzyFantom]

@FizzyFantom 

That's pretty nice of your friend to do that. Question! Would this math error code pop up on my screen or would I have to look for it? Basically what I'm asking is where would it be located?

And how long should I run Prime95?

Any errors will appear in the thread windows like this:

http://forumscdn.tweaktown.com/attachments/overclocking/4761d1340696213-z77a-gd65-i5-2500k-overclocking-how-start-prime95-sample-error-message.jpg

 

I would recommned you run it for a couple of hours to ensure it's working properly. You should run for 24 hours to make sure it is completely stable, but just for checking behaviour with different settings a couple of hours should show the changes (we found that after 10 minutes the defective CPU failed, but your results may vary)

 

 

@FizzyFantom

Also, should I turn on "Round Off Checking? What does that do? Its under the Advanced setting toward the top.

What setting should I put Prime95 on for my Test?

I've read that round of checking is on by default in all stress tests, so don't worry about it. As for what stress test, I use in-place large FFTs, lots of heat, and RAM is tested a little.

[Mojo-Jojo]

Can you check what that TMPIN1 is? It reports way too high of a max. temp.

[Novalife818]

@

I have no clue... I looked it up and some people said it was a mess up my HWMonitor

[Novalife818]

@JvHummel 

@FizzyFantom

@Needalight

Hey guys thanks for all your help. I am currently researching on some changes in the BIOS that may be affecting my results. I ran a test for about an hour and still had  the same results ): When I started the test everything was good for about a minute but than began to drop and go up again.....

[Novalife818]

@FizzyFantom

@

@Needalight

 

Thanks for all your guys help.  I am currently looking into the BIOS for some "cool and quite" setting I should turn off... Anyway if you guys have anymore recommendations that would be Great!! Below are my results after a bit of time testing.... );