FX8350 throttling

C

Castor Troy

Weaksauce
Joined
Jul 2, 2004
Messages
77
I recently moved my system into a new case and added a water cooler, and am now having throttling issues

System specs:
Asrock 990FX Extreme3
FX8350 with Corsair H55(dual fans in push/pull)
16gb Crucial Ballistix DDR3
Sapphire Radeon 7870
Nanoxia Deep Silence 2 case


CPU idle is reported as 27C by the Asrock tuning software. Running Prime95, within a few minutes it gets up to about 55C. The problem is, after about 30 seconds at 55C, it throttles back to 1390mhz across all cores for about 8 seconds, and after the temp hits 40C, the speed jumps back up to 4ghz until the temp hits 55c, and the cycle repeats.

What seems odd is, neither the radiator, nor the radiator exhaust seem to rise above ambient. The radiator feels cool to the touch(the radiator water intake feels slightly warm, but only slightly). I hooked the waterblock/pump up to my fan controller to make sure it was getting full power(reporting 1503rpm when connected to motherboard), and that didn't really seem to make a difference. I know the pump is working though, because when I lowered the fan controller to minimum, the idle temp goes up a few degrees pretty quickly.

I tried disabling all the different core throttling stuff in the bios, but that didn't seem to have any effect.

The one thing I did notice is the VRM and the northbridge heatsinks seem very hot. I wouldn't want to hold my hand on the VRM heatsink for more than a second. Could this be the cause of my throttling? After doing a little reading, throttling due to VRM overheating does not seem to be uncommon on some 990FX boards.

Here's a pic of the setup(before I added the second pull fan to the radiator)

newcase.jpg
 
check your temps with another program.. like aida64 or Hwmonitor, maybe the asrock tuning app its showing the socket temp and not really the CPU temperature, most manufacturers app like that tend to read from the socket temp not CPU itself..

also, according to the picture that radiator ins't in push/pull config.. just push because its only 1 fan.. also the power connector of the pump should be in a header with no speed regulation, in BIOS should be: "Control Fan: deactivate" or "OFF" that will allow the mobo to always send full power to the pump.. o say this because the pump should be running at ~2200RPM more or less as far i can remember, not 1500... check that first..
 
Lots of good points here. Make sure your cooler is seated correctly on the cpu. Recheck, examine the paste pattern (is it even or?) If the radiator doesn't seem to be absorbing heat, why?
 
(edit: Wow, I was off by a country mile, nevermind.)
 
Last edited:
It's your bios settings. One of them tries to keep the processor at a certain temp by throttling it. On my Asus Sabertooth I think it is the APM. I'll reboot and check for you in a second.

Yes, it's call APM. Application Power Management.
 
Last edited:
My usual advice (and assuming your water cooler works, of course):

1) Don't overclock.
2) Disable Turbo core.
3) Set LLC to disabled.
4) Undervolt the CPU.
5) If it still throttles, put a fan to blow to the VRM. Water Cooling is very bad for VRM cooling.
6) Curse Asrock for selling a board claiming to support specific CPU model and then after some time, quietly remove it from supported CPU list.
 
I'm reasonably certain it's the VRMs. When I had this motherboard in my old case, I had a large Xigmatek heatpipe cooler on it. Temps would hit 65C before throttling, which is why I went with the watercooler. 10C drop in temp, still throttling.

Araxie: I saw no difference in temps when the pump was connected to my fan controller @ full speed, vs connected to the motherboard header

Skripka: It's a Coolmax CUG-700B. It had no problem keeping up with a 1090T and two 7870s in Crossfire, so I don't suspect a PSU problem. Nice to see they dropped support for my CPU after I bought it :|

cageymaru: I disabled everything corespeed related in the bios, including APM

Faethon: I tried 1-3. Pretty sure I'm going to end up replacing this motherboard :(
 
Castor Troy said:
Faethon: I tried 1-3. Pretty sure I'm going to end up replacing this motherboard :(
Click to expand...

I am afraid you may have too, but try undervolting the CPU (at stock clock) too, it's the most heat-reducing action you can take. Drop voltage to the CPU, run Prime95, if it's stable, drop a bit more, repeat...

I have 3 970Extreme3 and 1 970Extreme3 R2.0 myself and i had thought to buy an 8320 when they go EOL and become dirt cheap. But now i have my doubts. Maybe i will get this one first: http://www.newegg.com/Product/Product.aspx?Item=N82E16813128651

I haven't made up my mind yet though.
 
Its likely not due to CPU Heat.

Its likely due to the power circuits not being able to handle the power draw of the 8350 cpu. Causing excessive VRM temps, and throttling. Its well known that most 4-1 phase boards cannot handle the 8 core cpus. You need a properly designed 8+2 phase configuration with good cooling on the VRM and Northbridge.


If you wish to use your current board, then I would suggest adding active cooling to the VRM, and Northbridge. Cpu should run cool enough with your cooling.

Other suggestions would be to disable a CPU module in bios. This will reduce power consumption and thermals.

Last suggestion if nothing else works replace the motherboard with a FXA 990 board with proper VRM and support for the octa-core cpus. My suggestions for boards would be.

Asus Crosshair V (formula Z or reg)
Asus Sabertooth
Gigabyte Ud7
Gigabyte Ud5
Gigabyte Ud3
ASRock Fatal1ty 990FX Killer AM3+
ASRock 990FX Extreme9
 
Yeah, I just ordered an Asrock Fatal1ty 990FX killer. I'll get a quad core or something and use the extreme3 for an HTPC I guess.
 
I've had so many problems with my 8320 throttling that I decided to just say f it, I'm turning off throttling. The problem isn't your CPU cooler, its the VRM. I don't think there are any mobos out there that can truly cool these things sufficiently with just heatsinks on the VRM. I bought a pretty powerful fan to put on the side of my case which is now blowing almost directly on the VRMs and that really helped the issue.
 
I've had the same exact problem. My 8320 dips to 1.4 ghz if the VRM get too hot. I've got a few extra case fans now and one blowing right on em. Seems to help.
 
Edit - Nevermind. Just saw this thread is nearly 2 years old.
 
You must log in or register to reply here.
Back
Top