Im toying around abit with some overclocking atm, but my MB(im guessing) is really acting wierd, else im doing something really wrong.
If i leave the CPU on stock speed, im getting the best performance, and if i overclock to lets say 4,2GHz what happens is the clock speed is actually clocked down when i run lets say prime95.
Usual scenario is i clock it to 4,2 which is stable. But when i run prime95 i can see through taskmanager that the CPU is throttled down to as low as 3,4GHz.
If i leave it at stock 3,7GHz(Im running a 7850 APU). It just works at 100% utilization with no fuzz.
I tested on Cinebench and overclocking actually has a deffinately negative impact on the result. which is very odd that a 4,2GHZ clocked CPU scores lower then a 3,7GHz.
My guess is you just got the best from the silicone lottery. I am the same. I have 760K that can't handle 4,2 stable on FM2A88X-Extreme6+...
Doesn't matter if i clock to 4,1. heck even 3,8. the second i disable the auto function on multiplyer this happens. And the higher i clock the lower the CPU gets clocked to when under "pressure".
Is your motherboard the Asus A88XM-A?
I think that that motherboard, whether or not it is the USB 3.1 variant, doesn't have any heatsinks on the MOSFETs - the hottest component that makes up the Voltage Regulator Module (VRM). It is also only a 3+2 phase, so it is not meant for hardcore work.
What is probably happening is that overclocking it is probably sending too much voltage through the VRM, which is causing it to get too hot, so it throttles the CPU to prevent overheating/damage. You can try manually lowering the voltage to help, otherwise, you'll have to find a way to supply more air to help cool the VRM.
I have the 7870 on an gigabyte 88 board and a 7850k on a MSI 68 board.
First are you using the stock cooler and are you using an aftermarket GPU or just iGPU?
ok 1 month later....finfet doesn't suck watts like vishera. On my 7850k with a cheap T2 cooler I went for an iGPU overclock. 12 percent increase in star-swarm frame-rates I think. When I pushed it higher then 900 or 860 I got less framerates and some thermal throttle on the cpu side.
Really sounds like he is using the stock alum cpu cooler
I kind of gave up on OC'ing this CPU. I litterally tried everything available to me for setting up, and fiddle with, im running a non-stock cooler as well, temperature is 60C at most when running 4,2Ghz.
But this one still puzzles me though, everytime i overclock the cpu, it litterally does the detrimentally opposite once i push it with lets say cinebench, where if overclocked to 4,2Ghz, it would just throttle the cpu to 3,4Ghz once cinebench starts rendering e.g. The cpu works at max capacity.
Tried disabling all power management, and completely taking over any clock control in the bios. Heck even told windows to only allow the cpu to throttle between 100-100%. But all with the same result.
That actually sounds like a reasonable explenation. Atleast the behavior seems much like it termal throtteling, except all the CPU is not the cause it self, so some outside part which causes the throtteling would explain it.
I spent 5 minutes creating these shitty visuals, but this will give you a good idea of what you're dealing with.
In this first image, I have outlined the whole Voltage Regulator Module (VRM) in red:
(There are two boxes: the larger left one has more of what you need to be concerned with, the higher, smaller one is the Integrated Circuit that controls the whole thing.)
This image outline the other specific components of a VRM: The Inductors/Chokes, Capacitors, and the MOSFETs.
Capacitors are outlined in yellow, the Chokes in Orange, and the MOSFETs in Red.
The MOSFETs are what concern you the most, since they get the hottest.
If you happen to have an extra fan lying around, you can try to find some way to mount it so it provides airflow to your motherboard. That might be the cheapest way to do it - other than trying to undervolt your CPU. (What voltages are you running at, anyway?)
If you're willing to spend a bit more more money, you can buy a fan specially suited for that purpose: Like this.
Alternatively/Additionally: I've used these MOSFET heatsinks before.
EDIT: I think @MisteryAngel is more of the components expert, perhaps she has some input.
Im going ZEN in hopefully a few months so honestly its not worth it. Once the ZEN is release im turning this computer into a play FFn(final fantasy) on my tv computer.
But it still annoyes me that something as simple as overclocking this rig failed.
The GPU clocks like a champ though it should be noted, were talking 966Mhz, 2400Mhz ram(id say much like a PS4 for games performancewise). i believe it is without even half a breath, only ever encountered 1 game which caused it to shut down at that speed, since it appearently was very intensive on cpu and gpu at the same time(combined they hit 90-100 degrees while massively overclocked on the gpu, and since gpu and cpu are on the same dice, it became to hot). And still it took 2 hours+ before emergency shutting down. CPU clock alone though, sigh......
The motherboard is not made for overclocking...
4pin EPS connector, no VRM cooling, 3+2phases VRMs...
And if you are "lucky" like me and have a CPU that can't OC at all, well...
This is definitely true, it's not made for overclocking, but it still is capable - if only barely. I have the A88XM-A/USB 3.1, and I can run the Athlon X4 880K at 4.5ghz at roughly ~1.5volts. I do this with the (pseudo)Wraith cooler it came with running at full tilt, so it will keep the VRMs cool enough, and the VRMs still run on the hot side, but it doesn't throttle.
@Lauritzen - have you tried AIDA64 as a stresstest? Prime95 sometimes, unwittingly, messes with voltages, and otherwise causes a lot more heat than what your CPU would realistically be put under load. AIDA64 also allows you to monitor the voltages.
All i can see if i stress the CPU even if overclocked to lets say 3,8Ghz from 3,7 it start throttling like a MOFO, 3,7Ghz has more performance then 4,2Ghz by a factor of like 10-20% on cinebench, and if i have taskmanager running besides cinebench it i can see the CPU actively throttels like champ down to what a nintendo can handle.
If i tell the BIOS to just hey you handle this whole clock frequency thang, it just runs and turbos and what not, if i try and take control, its boom instant 3~3,5Ghz city. Unclocked i barely touch 50 degrees, clocked to 4,2 were talking 55-60 degrees so the cpu is not throtteling due to termals. But if some MOBO component is forcing the throtteling it makes alot of sense.
Yeah well i have not looked that much into the fm2+ platform personaly.
But in terms of the vrm configuration, you are correct.
This 3+2 implementation is very lackluster for overclocking.
Of course it was a fairly cheap motherboard, so there isnt realy anything to blame on the board it self.
Which particular parts used in the vrm, i could take a closer look it it.
But i think that we can all agree that this isnt an overclocking board.
Next to that i have also readed that some of the Athlon´s 860K and or 760K seem to have issues with faulty temp sensors, and that was also effecting overclock potential of those chips.
Since the 7850K is basicly based on the same chip as the 860K, it might also be an issue with those.
Not fully sure if this issue was just according to a particular batch of chips or the whole line up.
Im guesing it is either M$ who has some VERY bad support, or else it has to do with the UEFI. Basically it "should" it should in a perfect world be you tell your CPU to run at xx speed, and it does so.
Again i can OC the GPU part like a champ(like 25-30%) on the exact same chip, the CPU even if GPU is disabled though, its just bad, really bad. To a point where i guess if i overclock it to 3,7Ghz(same clock as auto). It would start throtteling.
Probably the motherboard that holds you back.
Do you overclock from within the OS using Asus software suite or AMD overdrive.
Or do you overclock straight from the bios it self?
According to your post above, the temps on the cpu do look good to me.
So i assume that the faulty temp sensor is most likely not your issue.
tried em all, even limited windows throtteling to be between 100%-100% nothing helped(see power management).