FX-8120 is throttled by motherboard.

[ihos501]

Hello guys, I'm on a tight budget here(I'm on 17). My 8120 drops to 14x multiplier and I found out that this is because it is throttled by my VRMS (3+1).

If I run cinebench/intel burnin/ prime 95 or other stress test the multiplier drops and the temps of the VRMs go real high. I felt it and it was like about 85-90 degrees Celsius.

Specs:

Mobo: Asus M5A78L-M LX PLUS
Cpu: FX-8120 4.1ghz (200 x 20.5)
watercooled by: Zalman CNPS20LQ
cpu temps never go above 34 Celsius (even during a stress test).
Graphics: GTS 250 1 GB
PSU: Cooler Master 500W
RAM: Kingston HyperX Blu 8GB (1600)

I know my motherboard is crap however I would like to know:

If I get these: http://www.newegg.ca/Product/Product.aspx?Item=N82E16835708011, and put it on the VRMs and add a fan, would that stop the throttling?

 

[EarthDog]

It could... point a fan at them and see if that helps...

Does this throttling happen at stock clocks? Are you sure its not CPU temperature related?

 

[ihos501]

let me stock it and test.

I stocked it. 3.1 ghz. turbo boost to auto. I set everything to auto. ran y-cruncher and prime 95.

While stressing the clocks did not went to 4 GHz (turbo boost did not kick in as it is supposed to boost 4 cores to 4ghz.) The multipliers on some cores went down and up. some switching between 14x and 15.5x (stock). Cool and Quiet was enabled btw. VRMs were very hot.

 

[BeepBeep2]

Put heatsinks on the VRMs and point a fan at them.

I'm glad ASUS has a working Over-Temperature Protection. Many MSI boards will go until they catch fire. I've seen Gigabyte's OTP fail a few times too.

CPU temps at 31c, that is good. That means in real-life, you are around 50-55c. AMD FX CPUs have defective temp sensors that read roughly 20c too low. (I bet you've noticed idle temperatures very low, under your normal room temperature)

There may be an Over-Current trip on the board too, which means that when you draw so many amperes through the VRM/PWM, it will throttle or shutdown. If the heatsinks don't help, that would be my next guess as to the throttling, in which case you would need a better board or way to disable the OCP, which is not recommended.

 

[ihos501]

Well i'll get those heatsinks and put it. I however think im too young to spend that much money on computers eg. Sabertooth 990FX (thats for the old guys who are working) im still in high school. I love my FX. I think its a great buy but my gpu is bottlenecking.

 

[Lordred]

Disable APM

 

[ihos501]

Do you guys think my psu is struggling?

 

[trents]

Do you guys think my psu is struggling?

No.

I think you can get those mosfet copper heatsinks cheaper. Try looking at Sidewinder Computers web site. That shipping cost from NewEgg is unncessarily high. As someone else said, try putting a spot fan or fans to blow in the are around the CPU socket and the mosfet/VRM area.

 

[caddi daddi]

also disable cool and quiet in the bios.

 

[caddi daddi]

Disable APM

also disable cool and quiet in the bios.