Sudden drops in CPU utilization from CPU stress test

[Jaculus]

I was doing a stress test in prime 95 and experienced these drops in CPU performance. http://imgur.com/gMo3gUb. My processor is AMD FX-8320 and my motherboard is 970A-G43

Any suggestions on what is happening? It seems systematic

 

[kanewolf]

Something is probably overheating. Could be voltage regulators, could be CPU. What type of cooling do you have on the CPU? AIO water? If so then there may not be enough airflow to the voltage regulators.

 

[Jaculus]

Something is probably overheating. Could be voltage regulators, could be CPU. What type of cooling do you have on the CPU? AIO water? If so then there may not be enough airflow to the voltage regulators.

Yeah my MOBO doesn't have anything for cooling the VRM so it's quite likely to be that. When running the test my CPU didn't exceed 50C using an hyper evo 212.

 

[kanewolf]

The EVO should move air over the voltage regulators. Do you have an exhaust fan on the back panel above the I/O ports? Have you tried the same test with the side panel off to see if it is lack of inflow air?

 

[Jaculus]

The EVO should move air over the voltage regulators. Do you have an exhaust fan on the back panel above the I/O ports? Have you tried the same test with the side panel off to see if it is lack of inflow air?

I do have 2 case fans, but I positioned the CM 212 EVO kind of at 90 degrees to the case fan (so the logo would be shown correctly). I tried using a regular fan with the side panel off and it worked better. I think something like this would be the solution:
http://www.ebay.com/itm/20PCS-Lot-Aluminum-MOS-Mini-IC-Chipset-Cooling-Cooler-Heat-Sink-Heatsinks-/251233475838?hash=item3a7eae9cfe:g:rcgAAOxyqKVRidZf
http://www.ebay.com/itm/20PCS-Lot-11x11x5MM-IC-Cooling-Cooler-Mini-Aluminum-Heatsink-For-Chip-Cooling/221320177126?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20131003132420%26meid%3D03b5d9acd9ec41fbae415fbb2e2bbf62%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D251233475838

 

[kanewolf]

Even though you may not like the look I would recommend you put the EVO so that the air is blowing from the front of the case to the back. Those components between the CPU socket and the I/O ports are the VRMs. A fan directly above the VRMs as an exhaust would then get the heat out of the case.

 

[Jaculus]

Even though you may not like the look I would recommend you put the EVO so that the air is blowing from the front of the case to the back. Those components between the CPU socket and the I/O ports are the VRMs. A fan directly above the VRMs as an exhaust would then get the heat out of the case.

That would probably work better as the air would circulate more efficiently. I will probably get the mini heatsinks anyways just to be sure the VRMs are as cool as they can be!

Thanks for the advice!