Unstable AMD A10-7870k

[Thomas_145]

I've had the APU for only a few months and I've never had any problems with it. Suddenly one day the frequency readings on the CPU just kept fluctuating between 3800MHz and 1700MHz. All 4 cores change frequencies at different times but quite often, 2 cores will fluctuate and go back to normal then the other 2 then fluctuate. I've renewed the thermal paste and bought a better and brand new cooling fan. Temperatures are not the issue. I've used memtest and HDTune to scan for any errors in memory or on the hard disk but it's all fine. I've also tried a benchmark test on Ubuntu and Linux and even on them it fluctuates. Could this be anything to do with a CPU problem?

 

[Herobrine]

Ubuntu ia Linux. And that's called throttling. Check the temperature. It could be overheating. My A10 6800 does that also. But in 3.1-4.2Ghz range. It's probably power saving feature AMD didn't implemented properly as always

 

[Thomas_146]

The temperature is perfectly normal. I monitored the CPU for around 2 hours under a stress test and the CPU temperatures where extremely low, settling at around 30-40 degrees and even lower sometimes and that's understress!

 

[jtk2515]

is it throttling under 100% load?

 

[Thomas_146]

If I think I know what you're asking, the frequencies are dropping when 100% is reached.

 

[jtk2515]

what program are you using to load your cpu?

 

[Thomas_146]

I'm using Prime95 and also just testing via playing some games.

 

[Herobrine]

The temperature is perfectly normal. I monitored the CPU for around 2 hours under a stress test and the CPU temperatures where extremely low, settling at around 30-40 degrees and even lower sometimes and that's understress!

It could be something with the way Ubuntu handles the CPU then. I don't know much about Ubuntu but under Windows you can limit how low and high the CPU can get.

 

[jtk2515]

try cinebench. when i'm testing with prime 95 my 4.9ghz over will clock down to 4.6ghz. try that 1st to see if your really getting full load.

 

[Thomas_146]

Tried cinebench and it's still clocking down towards 1.7/1.8ghz.

 

[jtk2515]

I would try updating your motherboard bios. Also could you list what motherboard you are using to help us try and narrow down the problem.

 

[Thomas_145]

All bios is up to date. The motherboard is a gigabyte Ultra Durable F2A78M-HD2 with a FM2+ socket.

 

[jtk2515]

This is something to try.
"Hi, I'm an A10-7850K and Extreme 6+ owner which could come in your Help regarding the throttling issue:
As you noticed the throttling is related to drawn power, and so basically the system is making the APU running on a lower P-State, what I've done is to change the P-states with the use of AMDmsrtweaker in its 1.1 version (in fact you can just change p-state number 5, which is the state where the CPU is put when GPU is loaded).

What is also tricky and I don't think many of you have noticed is that GPU, when the entire APU (CPU+GPU) is loaded, makes "jumps" between the frequency you have set in the bios and 450Mhz, causing stuttering and other annoying things (you can see it with a GPU clock graph like the one in MSI Afterburner).
To avoid these jumps you should first install the latest beta version of MSI Afterburner, and then in the setting disabling ULPS and activate the unofficial overclocking mode without Powerplay support. After rebooting you have just to move the slider around GPU Core, it's not important to change the value, but just to make the button "Apply" pushable. Once you'll push "Apply" the frequency will be stuck at the frequency you put in the Bios.

The CPU trick (with AMDmsrtweaker) and the GPU trick are temporary, meaning that at every reboot you will have to run the customized .bat file (CPU) and do the "Apply trick" in MSI Afterburner."


Also could try cooling the VRM's better to see if that helps