Thermal Throttling @ 50c ??

[Nicholas Peyton]

Hi guys,

Got something REALLY strange going on here.

Thermal throttling at only 50 degrees C (CPU socket temp) and 24 degrees C (package temp):

AMD FX-8350:
4.8GHZ @ 1.488v ( + default BIOS setting of +50mv CPU voltage offset)
RAM 2133mhz
NB & HT: 2600mhz

I'm running a water chiller. Water temp about 10c.

On air/non chilled water I wasn't throttling until socket temp was hitting 62c (sometimes on rare occasion even 75c).

I am at a total loss; in AMD OverDrive the 'thermal margin' is also reading 45c

"Core Temp" app also shows CPU temp at 24c with TJ max at 70c.

I'm running a small FFT; 1st test (maximum heat) on PRIME95. (But that is irrelevant to be honest; as far as I'm aware I shouldn't be throttling until CPU hits 62c?

Anyone able to shed any light on this?

Would be much appreciated!

Thanks a million,


Nick Peyton

P.S.

Thought it might be my VRM phases:

But I have a dedicated 3500 RPM fan that I attached directly onto the motherboard VRM heat sink.

It actually does such a good job the heat sink is so cool I can keep my finger on it and doesn't even feel too hot. Only 'very warm'.

If I remove the fan, of course, I couldn't keep my finger there for more than a second or two......

I also haven't increased my overclock, since getting the water-chiller... I'm just running a hotter test (not a test that consumes more power) -- just more heat.

I was only doing these tests to compare a few thermal pastes. Then my session got interrupted by this rather strange throttling. :-(

 

[Mr.Scott]

Asrock board.
It is VRM throttling.
I blew up a couple of Extreme 9's.
Their hybrid digital/analog VRM setup can't handle the overclocked FX's.
Asus boards are the only one's that can.

I'm just running a hotter test (not a test that consumes more power) -- just more heat.

Lol. You get more heat because it's drawing more power.

 

[Nicholas Peyton]

Asrock board.
It is VRM throttling.
I blew up a couple of Extreme 9's.
Their hybrid digital/analog VRM setup can't handle the overclocked FX's.
Asus boards are the only one's that can.



Lol. You get more heat because it's drawing more power.

Lol, I hear what you're saying.

I know how it works though; but on PRIME95 there are three tests.

Small FFT - (Listed as max heat)
Large FFT (Listed as max power)

On the Large FFT my watt meter does indeed read a bit higher.
On the Small FFT my water meter reads slightly lower (but CPU still generates a bit more heat)

Anyway thanks for reply; gna do a little check and I'll be back in a minute (your post just gave me an idea)

 

[Mr.Scott]

Small FFT works the CPU hard. Large FFT works the memory, IMC, and chipset hard. You should be testing in blend.

 

[Nicholas Peyton]

Small FFT works the CPU hard. Large FFT works the memory, IMC, and chipset hard. You should be testing in blend.

I wanted a maximum heat scenario for comparing thermal pastes, that's what I'm up to lol

Anyway you were right; even though my VRM heatsink (with 3500RPM fan) wasn't too blisteringly hot to keep finger on. When I touched the back of the PCB (behind VRM) at back of motherboard, OUCH! (back of CPU was fine)

Begs the question; how good the 'contact' is between VRM and heatsink on these boards. Wouldn't surprise me if ASROCK's got a 6mm slab of thermal pad down there lol.

Well I've learnt my lesson; when ZEN hits the market I'll not be touching ASROCK.

I mean c'mon; my dream comes true.. I get the chiller.. my temps are under control at 45c at 1.5v but now my bloody mobo is holding me back? I mean ffs lol.

Anyway more importantly; I'm going to adjust my 'back of socket' fan so it aims at back of VRM instead of back of CPU and see if that gets me any extra headroom.

Be back in a minute....

 

[Mr.Scott]

You're gonna blow the board up. It's just a matter of time.
Doesn't matter how much heatsink or fan you put on the VRM.
Only 990 FX boards that are worth their salt overclocking are
the CH
the Sabertooth
and the 970 Aura.
In that order.

Well I've learnt my lesson; when ZEN hits the market I'll not be touching ASROCK

Zen will be a totally different animal. Their boards might be the best for Zen. Nobody knows. Keep an open mind.
Asus owns the market on 990FX boards though. That is a fact.

 

[Nicholas Peyton]

I'm back.

You were absolutely right.

I aimed, 3000 RPM Industrial, at the back of the motherboard VRM and all throttling's stopped: (so that's a total of 6500 RPM worth of fan dedicated to motherboard VRM now front + back)

Thanks Mr Scott, now I can carry on with my wee experiment

You're gonna blow the board up. It's just a matter of time.

Well lets just hope ZEN comes out before I do then; because I've got this chiller now and I just am not that patient lol...

You did ask a few days ago when I was going to go for the 5000+ (and I've got both tims sitting here).. as soon as I decide which one I'm going to use then 5000+ is exactly where I'm going.

 

[fullinfusion]

Wow I cant believe you hooked the chiller up but good on you!

You know you just opened a whole can of shit by doing so right, but still good on you!!!! nothing ventured nothing gained?

10c and I bet your room temp is 18-20c.... if a single drop of condensation hits the cpu pins or pads its a funky situation right!

wanna see condensation look here ... that's below 0c

 

[OneMoar]

those vrms are gonna go pop pop POP no matter how well you cool them
amd chips are aweful about power consumption

also that metal plate held on with putty makes me hella nervous thats asking for a short and with that much ampage running though the vrms thats a recipe for fire

 

[fullinfusion]

those vrms are gonna go pop pop POP no matter how well you cool them
amd chips are aweful about power consumption

also that metal plate held on with putty makes me hella nervous thats asking for a short and with that much ampage running though the vrms thats a recipe for fire

Those VRM's wont go pop pop poof.... Its amd bro!!! They handle allot of power... I know, I owned one for some time.. but then again I've ALWAYS used ROG mobos! so yeah you might be right

and yes the putty makes me nervous too but as long as it hangs on kudos to the op!

 

[phanbuey]

holy crap. That is an awesome cooling setup. Is this the chiller from that other thread? Can we get a pic of the setup?

also that's not a metal plate. Some sort of card.

 

[fullinfusion]

holy crap. That is an awesome cooling setup.

also that's not a metal plate. Some sort of card.

It's a I WANT COOLER system with not much know how... Plus it shouldn't even be used in that system, It's a waste of money... Get down to -10c and ok maybe its worth it but +10 I don't think so

 

[Nicholas Peyton]

those vrms are gonna go pop pop POP no matter how well you cool them
amd chips are aweful about power consumption

also that metal plate held on with putty makes me hella nervous thats asking for a short and with that much ampage running though the vrms thats a recipe for fire

its no metal plate, its plastic. And the putty (or blue-tack) isn't holding any weight. It's just there as 2nd defence in case it should become wobbly.

The fan is superglued to the plastic plate.

Not an elegant solution no; but I can assure you the fan isn't going anywhere.

It's a I WANT COOLER system with not much know how... Plus it shouldn't even be used in that system, It's a waste of money... Get down to -10c and ok maybe its worth it but +10 I don't think so

I had the choice of spending 80-100 and adding a 2nd radiator (which I needed anyway). Or spending an extra 100 (£200) and snapping up the chiller off Ebay.

Anyway one step at a time.

 

[Mussels]

damn i was coming here to say it was the VRM's, was beaten to it.

thought i was a genius for figuring out why three of my friends FX systems (all asrocks) were throttling at stock speeds, goddamn terrible board designs it seems :/

 

[Nicholas Peyton]

damn i was coming here to say it was the VRM's, was beaten to it.

thought i was a genius for figuring out why three of my friends FX systems (all asrocks) were throttling at stock speeds, goddamn terrible board designs it seems :/

yeah hmmz I wonder if the VRM heatsink is removable, I could try swapping out with a better quality thermal pad

I'm not throttling anymore with the extra fan, but its awfully noisy and jokes aside I'd still rather prolong the boards life if possible#

Then again i'm not running it flat out 24/7. Probably lucky if it gets a work out like that more than 25 minutes every few days when I'm feeling adventuress. Which lately has, I admit; been little more often. lol.

 

[Mussels]

one of the asrocks i fixed didnt even have a stock heatsink on the VRMs, and couldnt handle an FX 6 core at stock clocks, undervolted.

IMO they either cheaped out on the VRM's, or set the thermal throttle too low

 

[Tuna Yücer]

Well you should not stress CPU's with Prime95. IMO It hammers CPUs heavily.

Use Aida64 System Stability Test.

 

[Mr.Scott]

Well you should not stress CPU's with Prime95. IMO It hammers CPUs heavily.

Use Aida64 System Stability Test.

That's the point of using P95.
Aida is not strong enough.
You can pass 24 hrs of Aida and still crash during gaming or benching.

 

[Mussels]

all these people saying you shouldnt run these stress tests... why the hell not? to avoid the fact your systems unstable, or incapable of full load (like with faulty VRM's)

my friend whose system clued me into this issue had thermal throttling kick in running his HTC vive - the extra load triggered the throttling and made his system crap out. If these tests expose a problem with your setup, hiding your head under the sand wont solve anything.

 

[EarthDog]

I'm with you on the cpu.. though these days I'm aida (normal and FPU only) and Realbench stress test and that's it. Works for MY uses.

Now, furmark on the gpu, different story. It's so bad, years ago both amd and Nvidia said not to run it (power virus). If you run it on nvidia cards, it drops boost bins IMMEDIATELY. This is not a function of the card not being able to handle it. It's how they respond to that program So how effective is it when you aren't testing the same clockspeed you thought you were? You never end up testing the clock you wanted to.

 

[Nicholas Peyton]

Well you should not stress CPU's with Prime95. IMO It hammers CPUs heavily.

Use Aida64 System Stability Test.

It depends on what your doing.

I was comparing:
Thermal Grizzly Kryonaut 12 w/MK (Industry's best normal thermal paste)
with
Thermal Grizzly Conductonaut 72 w/MK (Industry's highest w/MK rated Liquid Metal).

The more heat I could generate; the more accurate my results.

Being throttled by my motherboard VRM phases would of prevented an accurate result, which is why I asked for help. (Which members here were kindly able to provide) enabling me to continue with the experiment

 

[eidairaman1]

Those VRM's wont go pop pop poof.... Its amd bro!!! They handle allot of power... I know, I owned one for some time.. but then again I've ALWAYS used ROG mobos! so yeah you might be right

and yes the putty makes me nervous too but as long as it hangs on kudos to the op!

Either ROG or TUF.