FX-8120 temps

[Joni]

Thanks alot for your help, got this to 4.8 GHz stable but I think 4 GHz is enough. One thing that puzzles me though is that when at stock settings vcore jumps sometimes to 1.35 when running geekbench, then changing multiplier to 20x (4GHz) and disabling AMD Turbo mode I get max vCores about 1.24 and overall vCore is much lower than at stock settings. Why is that?

I mean, on default AMD Turbo when it's at 4 GHZ it has 1.38 vCore, if I overclock to 4 GHz it's stable at 1.24. Why does it use so hight voltages on stock settings and should I bump up the vCore from 1.24 to 1.38 even if it's prime stable?

 

[ssjwizard]

No you should not up the voltage to 1.38v unless absolutely necessary. If its prime stable and not crashing on you then keep that vCore nice and low.

 

[Joni]

Yes it's Prime stable, i'll leave it to that, thank you.

 

[Joni]

Is there any program that would give better indication than Prime95 of how high the temps get, I mean something that stress the CPU to the levels I would get on normal use.

 

[Ravara]

im still wondering why some of you can get that low voltage.. im running 1,35 Vcore and thats with 1tap in the voltage, perhaps its different from each mobo??

 

[Joni]

im still wondering why some of you can get that low voltage.. im running 1,35 Vcore and thats with 1tap in the voltage, perhaps its different from each mobo??

With my chip+mobo I get best results with LLC. I leave everything on default, except I disable AMD Turbo and then adjust only the multiplier.
4.0 GHZ / LLC regular (0%)
4.2 GHz / LLC medium (25%)
4.3 GHz / LLC high (50%)
4.4 GHz / LLC ultra high (75%)

For example 4.4 GHz on LLC ultra high, It has vCore 1.320, if I do that manually I have to adjust the vCore much higher, don't really know why.

 

[trents]

Is there any program that would give better indication than Prime95 of how high the temps get, I mean something that stress the CPU to the levels I would get on normal use.

Well, just run your games or whatever software applications you normally run and have HWMonitor open on the desktop to record temps. HWMonitor not only records current temp but max temps attained. But the reason we run Prime95 is to check for stability and to ensure that we are stable. Yes, it puts more stress on the system and makes more heat than normal apps but that's the whole point. IF Prime stable for an extended time it gives us a little hedge.

 

[trents]

With my chip+mobo I get best results with LLC. I leave everything on default, except I disable AMD Turbo and then adjust only the multiplier.
4.0 GHZ / LLC regular (0%)
4.2 GHz / LLC medium (25%)
4.3 GHz / LLC high (50%)
4.4 GHz / LLC ultra high (75%)

For example 4.4 GHz on LLC ultra high, It has vCore 1.320, if I do that manually I have to adjust the vCore much higher, don't really know why.

LLC supplements the voltage you the vcore nominally set to in bios. It will give a small supplement when the CPU is idling and it will give a larger supplement when it is under load (LLC stands for Load Line Calibration). The idea is that it allows you to get away with a lower voltage when not under stress (load) but give you more juice to maintain stability when you are.

 

[Ravara]

With my chip+mobo I get best results with LLC. I leave everything on default, except I disable AMD Turbo and then adjust only the multiplier.
4.0 GHZ / LLC regular (0%)
4.2 GHz / LLC medium (25%)
4.3 GHz / LLC high (50%)
4.4 GHz / LLC ultra high (75%)

For example 4.4 GHz on LLC ultra high, It has vCore 1.320, if I do that manually I have to adjust the vCore much higher, don't really know why.

as trents said aswell it supports ur cpu voltage, but it can also make you spike on high clock ive turned my LLC to lowest cuz when i have a +1 increment in voltage so that i hit 1,36 it can spike or even throw itself up to 1,44 which is more than i have nerves for

 

[trents]

Yes. The intention is to allow 24/7 voltage to be lower than what you need to be stable at peak loads.

 

[Joni]

LLC supplements the voltage you the vcore nominally set to in bios. It will give a small supplement when the CPU is idling and it will give a larger supplement when it is under load (LLC stands for Load Line Calibration). The idea is that it allows you to get away with a lower voltage when not under stress (load) but give you more juice to maintain stability when you are.

Thats how I've understood it but after testing I noticed that with LLC I can get stable OC on lower voltage, I mean running prime95 on 4.4 GHz for example I get peak voltage 1.320 with LLC enabled but if its disabled I have to go to 1.360 to get it stable.

 

[ssjwizard]

Ya, if you tune your board right, and let LLC do its thing you can take FX very far at low heat/volts.

 

[Ravara]

ehm.. the LLC increases voltage when needed = when you game you actually have a possible chip frying like hell cuz it will increase as much as it is need on auto or similar, thats what i saw with LLC on with my 4,4ghz stable clock it hitted 1,45v sometimes more but now with my 4,2ghz and LLC at lowest i max hit 1,39v which makes my life a bit easier "i normally start my HWmonitor since i like monitoring my pc "

imo LLC is a dummy help for Ocing but also like playing with fire.. most recommend turning it the lowest as far as i have seen it

 

[ssjwizard]

LLC increases voltage when needed = when you game you actually have a possible chip frying like hell cuz it will increase as much as it is need on auto or similar.

Ideally when overclocking(or building in general) you should do your best not to leave ANY settings on AUTO! LLC especially. You start at the lowest setting and if you need more you turn it up. Ultra LLC will give you a simply stupid amount of vCore boost. I think my FXa-UD3 on highest LLC adds 0.15v which is out of freakin hand. On low it adds about 0.03 on the 2nd setting it adds about 0.05 - 0.06 which is more than most should need for 24/7 clockspeeds.

 

[Joni]

Ideally when overclocking(or building in general) you should do your best not to leave ANY settings on AUTO! LLC especially. You start at the lowest setting and if you need more you turn it up. Ultra LLC will give you a simply stupid amount of vCore boost. I think my FXa-UD3 on highest LLC adds 0.15v which is out of freakin hand. On low it adds about 0.03 on the 2nd setting it adds about 0.05 - 0.06 which is more than most should need for 24/7 clockspeeds.

Maybe there is some differences on how LLC works between Asus and Gigabyte?

I did some testing with 4.4 GHz. If I want to get it Prime stable I have to go over 1.360 V with LLC off, now if I change the voltage to default and just enable LLC UH (75%) it gives max vCore 1.320 V on 4.4 GHz and it's stable.

With LLC it gives better temperatures and needs less voltage to be stable on Prime.

I left Hardware Monitor open on the background and not once it recorded any weird voltage jumps on Prime95, benchmarks, gaming or heavy video encoding. It was max 1.320 V.

I have no idea how it is possible it requires less voltage on LLC.

 

[trents]

Yeah, that's weird. Do you still have Turbo and C1E enabled?

 

[Joni]

Yeah, that's weird. Do you still have Turbo and C1E enabled?

No, those and other green settings are off currently.

 

[ssjwizard]

I did some testing with 4.4 GHz. If I want to get it Prime stable I have to go over 1.360 V with LLC off, now if I change the voltage to default and just enable LLC UH (75%) it gives max vCore 1.320 V on 4.4 GHz and it's stable.

With LLC it gives better temperatures and needs less voltage to be stable on Prime.

Thats pretty much the behavior of FX. They are very good at handling dynamic voltage. This is one of the very important differences between the 9xx series and previous generations of AMD motherboards/CPUs. When the 900 series boards came out people complained about it alot to the manufactures and the response was these boards follow AMD specs for the zambezi architecture.

I run 4.2ghz on my 8120 @ 1.25v idle and after llc(level2) kicks in it will boost up to 1.29-1.32 depending on the load. Running with LLC disabled required 1.35v to keep the system stable because of the vDroop at load which resulted in all around much higher temps.

 

[Joni]

Thats pretty much the behavior of FX. They are very good at handling dynamic voltage. This is one of the very important differences between the 9xx series and previous generations of AMD motherboards/CPUs. When the 900 series boards came out people complained about it alot to the manufactures and the response was these boards follow AMD specs for the zambezi architecture.

I run 4.2ghz on my 8120 @ 1.25v idle and after llc(level2) kicks in it will boost up to 1.29-1.32 depending on the load. Running with LLC disabled required 1.35v to keep the system stable because of the vDroop at load which resulted in all around much higher temps.

That makes sense. FX was much better overclocking than what I expected, and with LLC I'm able to keep all my fans on low, I have to check the power led to see if my computer is on or off, this I expected would be impossible with the 124W CPU

 

[Joni]

Someone said on some other thread that NB overclocking is important on FX because of the longer instruction pipeline. Is that true, also if I up my NB to say 2600-2800 should I increase the HT link to 2600 also or leave it as auto? Does NB frequency have any effect on CPU temperature?

I'm running at 4.3 GHz @ 1.31V now and quickly tried to up the NB to 2600 and 3DMark11 physics went up from 7255 to 7355 so it seemed to have some effect.