FX8350 throttling with M5A78L-M/USB3 motherboard

[SlammichTheSorcerer]

Hi, for a long time now I've been having CPU throttling issues with what I assume is either my CPU or my motherboard VMRs. During intensive games, my fps would dip, along with my CPU and GPU-usage in frequent intervals.
I've applied Enzotech MOS-C1's to the VRMs which I feel helped the problem a bit, but not entirely. What else could I do to resolve this problem? Maybe a better CPU-cooler? I'd considered maybe getting another motherboard, but my case only supporting micro-atx limits my choices.
Is there maybe a way to clock back my CPU to help things out?

My specs are as follows:
MoBo: Asus M5A78L-M/USB3 Micro-ATX
CPU: AMD FX-8350
Cooler: Scythe Shuriken Rev. B
GPU: Nvidia gtx 970
PSU: Cooler Master G650M
Case: Cooler Master Silencio 352

Thanks in advance!

 

[GhislainG]

It most likely is the motherboard that isn't good enough for that CPU (particularly when installed in a quiet case), but did you make sure? It should be easy to determine where the issue is with AMD Overdrive; monitor the thermal margins while stress testing the CPU with Prime95 Small FFTs. Do they gradually drop or do they drop all of a sudden?

 

[Supernova1138]

You're pretty much looking at getting a new case and new motherboard to be able to reliably solve this problem, there are no MicroATX AM3+ motherboards that have adequate power delivery for the FX 8350. You've already applied VRM heatsinks, and those haven't fixed it, really the only other thing you could do is get a downdraft CPU cooler that blows air down onto the CPU and VRMs and hope that stops the throttling. If you're really desperate to avoid a new case, you could try undervolting and underclocking your CPU, which would reduce the power consumption and take some pressure off the VRMs, but you'd lose some performance in doing so.

 

[GhislainG]

You're pretty much looking at getting a new case and new motherboard to be able to reliably solve this problem, there are no MicroATX AM3+ motherboards that have adequate power delivery for the FX 8350. You've already applied VRM heatsinks, and those haven't fixed it, really the only other thing you could do is get a downdraft CPU cooler that blows air down onto the CPU and VRMs and hope that stops the throttling. If you're really desperate to avoid a new case, you could try undervolting and underclocking your CPU, which would reduce the power consumption and take some pressure off the VRMs, but you'd lose some performance in doing so.

The Scythe Shuriken Rev. B meets that requirement, but the fan may not blow enough air; there may be a way to increase its speed or replace it with a higher airflow fan. I agree that an ATX motherboard that properly supports that CPU in a larger case is the best solution.

 

[madmatt30]

The shuriken is borderline not enough for an 8350 really mate.
Its only a 100mm fan & doesn't really offer much airflow over the vrm area.

What are your hermsl margins in overdrive under load??
If cpu temps look OK & it is board throttling then there's a good chance you can tinker with voltages & llc which may help.
For starters though just straight out disable turbo core if you haven't already , it'll push 1.4v+ through those MOSFETs when enabled.

 

[madmatt30]

How you fixed those MOSFET sinks ?
In all honesty when I dropped them on the same board it actually upped the vrm temps by 2c so I removed them.

 

[SlammichTheSorcerer]

It most likely is the motherboard that isn't good enough for that CPU (particularly when installed in a quiet case), but did you make sure? It should be easy to determine where the issue is with AMD Overdrive; monitor the thermal margins while stress testing the CPU with Prime95 Small FFTs. Do they gradually drop or do they drop all of a sudden?

I haven't stresstested the CPU with that particular program, but when testing it with HeavyLoad it would always sharply drop and then jump back up.

You're pretty much looking at getting a new case and new motherboard to be able to reliably solve this problem, there are no MicroATX AM3+ motherboards that have adequate power delivery for the FX 8350. You've already applied VRM heatsinks, and those haven't fixed it, really the only other thing you could do is get a downdraft CPU cooler that blows air down onto the CPU and VRMs and hope that stops the throttling. If you're really desperate to avoid a new case, you could try undervolting and underclocking your CPU, which would reduce the power consumption and take some pressure off the VRMs, but you'd lose some performance in doing so.

Yeah, I've been thinking about downdraft CPU-coolers, since I feel like the issue really started once I upgraded the stock AMD fan with the Scythe one. Back in the honeymoon days she'd run just fine, but then I switched the fan and then transported it to my dorm and back. I figured either switching or transportation messed with it.

In case of underclocking, is it hard to get it done? And will it only cost performance and not longevity?

 

[Supernova1138]

It most likely is the motherboard that isn't good enough for that CPU (particularly when installed in a quiet case), but did you make sure? It should be easy to determine where the issue is with AMD Overdrive; monitor the thermal margins while stress testing the CPU with Prime95 Small FFTs. Do they gradually drop or do they drop all of a sudden?

I haven't stresstested the CPU with that particular program, but when testing it with HeavyLoad it would always sharply drop and then jump back up.

You're pretty much looking at getting a new case and new motherboard to be able to reliably solve this problem, there are no MicroATX AM3+ motherboards that have adequate power delivery for the FX 8350. You've already applied VRM heatsinks, and those haven't fixed it, really the only other thing you could do is get a downdraft CPU cooler that blows air down onto the CPU and VRMs and hope that stops the throttling. If you're really desperate to avoid a new case, you could try undervolting and underclocking your CPU, which would reduce the power consumption and take some pressure off the VRMs, but you'd lose some performance in doing so.

Yeah, I've been thinking about downdraft CPU-coolers, since I feel like the issue really started once I upgraded the stock AMD fan with the Scythe one. Back in the honeymoon days she'd run just fine, but then I switched the fan and then transported it to my dorm and back. I figured either switching or transportation messed with it.

In case of underclocking, is it hard to get it done? And will it only cost performance and not longevity?

Underclocking isn't any more difficult than overclocking, just dial back the voltage and reduce the clockspeed until it remains stable. It will cost you performance, but won't effect longevity aside from potentially making the CPU last longer due to lower voltage being pumped into it. Won't matter either way, the CPU will last until long after it is completely obsolete.

Transportation might have knocked the cooler loose, leading to high CPU temps and thermal throttling on the CPU, you'll want to check your thermal margins in AMD Overdrive and make sure the cooler is securely mounted.

 

[GhislainG]

You wrote "I haven't stresstested the CPU with that particular program, but when testing it with HeavyLoad it would always sharply drop and then jump back up." This indicates VRM induced throttling; a CPU doesn't behave like that. Basically the VRM gets too hot and it forces throttling by setting the CPU temperature to a very high value; the CPU frequency drops down to 1.4 GHz and then the VRM has an opportunity to cool down.

 

[SlammichTheSorcerer]

So, if I've got it right, as a short-term solution, I could underclock my CPU to strain my VRMs less, and for long term, look into an ATX case+mobo, that's it?

 

[Supernova1138]

So, if I've got it right, as a short-term solution, I could underclock my CPU to strain my VRMs less, and for long term, look into an ATX case+mobo, that's it?

Yeah, that about sums it up.

 

[SlammichTheSorcerer]

Alright, thanks for the support!

 

[madmatt30]

I will add here that the little Asus boards APM settings are 'over zealous' to say the least & this is something that cannot be altered in bios & can only be remedie completely by the use of amd msrtweaker.

Its absolutely possibly to get an 8 core fx running at a straight 4ghz on that board with no throttling issues.

In all fairness while its a 4+1 phase I've had those caps at 68c with no signs of throttling at all.

Do whatnive suggested for starters just disabling turbo , it makes a huge difference to clocks under heavy loads & will stop extreme variations in clock speeds.

At the moment your cooler is as big a problem as anything because its 'just about' good enough & no more than that.

 

[SlammichTheSorcerer]

I will add here that the little Asus boards APM settings are 'over zealous' to say the least & this is something that cannot be altered in bios & can only be remedie completely by the use of amd msrtweaker.

Its absolutely possibly to get an 8 core fx running at a straight 4ghz on that board with no throttling issues.

In all fairness while its a 4+1 phase I've had those caps at 68c with no signs of throttling at all.

Do whatnive suggested for starters just disabling turbo , it makes a huge difference to clocks under heavy loads & will stop extreme variations in clock speeds.

At the moment your cooler is as big a problem as anything because its 'just about' good enough & no more than that.

Alright, I've already throttled back the clock to 3,7ghz at around 1.25V-ish volts if I recall correctly, but I'll disable Turbo Core from now on when I get home. For coolers, what would you recommend that'd help cool my VRMs as well? I heard good things about Noctua's NH-C14S.

 

[madmatt30]

What country are you ??

The raijintek Pallas is the best buy if available , as good as the noctua IMO (better at vrm cooling) & should be half the price.

Absolutely 100% disable turbo core - its non beneficial on a lower end board & can be a csusebof erratic clock & voltage jumps under load.

 

[SlammichTheSorcerer]

In Belgium, both the Raijintek Pallas and the Noctua one are available to me, with the Pallas being a good 30 euro less yeah. Just checked, AMD OverDrive doesn't remember me turning off Turbo Core, so that's gonna be something I'll have to disable everytime, but if it helps out, then gladly. Should I still lower the CPU voltage from 1.3 to 1.26 and my clock too?

 

[madmatt30]

You want to be lowering voltage , clocks & disabling turbo in bios mate not with overdrive.

I'm UK so at work at the moment , later on when I'm home I will give you directions what to alter in the bios step by step.
I own the board myself so am very very familiar with it

 

[SlammichTheSorcerer]

Thanks, I couldn't ask for more!

 

[thamespeak]

You want to be lowering voltage , clocks & disabling turbo in bios mate not with overdrive.

I'm UK so at work at the moment , later on when I'm home I will give you directions what to alter in the bios step by step.
I own the board myself so am very very familiar with it

Hi, i know im a little late but im pretty sure i have the same problem, i could get a new motheboard as i recently got a new case that could fit one. Was looking at the but still arent 100% that the motherboard is the problem.

 

[GhislainG]

You want to be lowering voltage , clocks & disabling turbo in bios mate not with overdrive.

I'm UK so at work at the moment , later on when I'm home I will give you directions what to alter in the bios step by step.
I own the board myself so am very very familiar with it

Hi, i know im a little late but im pretty sure i have the same problem, i could get a new motheboard as i recently got a new case that could fit one. Was looking at the but still arent 100% that the motherboard is the problem.

That's easy; use AMD Overdrive to monitor the CPU thermal margins, then run Prime95 Small FFTs. Check how the thermal are dropping (slowly or all of a sudden) and if the frequency drops to 1.4 GHz. The results will help in determining if the issue is the CPU cooler or the VRM.

 

[thamespeak]

You want to be lowering voltage , clocks & disabling turbo in bios mate not with overdrive.

I'm UK so at work at the moment , later on when I'm home I will give you directions what to alter in the bios step by step.
I own the board myself so am very very familiar with it

Hi, i know im a little late but im pretty sure i have the same problem, i could get a new motheboard as i recently got a new case that could fit one. Was looking at the but still arent 100% that the motherboard is the problem.

That's easy; use AMD Overdrive to monitor the CPU thermal margins, then run Prime95 Small FFTs. Check how the thermal are dropping (slowly or all of a sudden) and if the frequency drops to 1.4 GHz. The results will help in determining if the issue is the CPU cooler or the VRM.

i disabled turbo clock and 2 of the cores as suggested before. all seems fine the MHz doesn't seem to be dropping and also it is still running on 100% on the task manager tab when before with the 8 cores it would drop very quick. im just going to change the settings back then ill give you an update. Thank you very much for the first reply also!

 

[thamespeak]

it drops from 3516MHz to 2913MHz when using prime 95 so it seems like some skind of throtteling? any ideas?

 

[GhislainG]

What motherboard? Some cheap one like too many people buy for an FX CPU? They draw a lot of power; therefore you need a quality motherboard with a very good VRM.

 

[thamespeak]

What motherboard? Some cheap one like too many people buy for an FX CPU? They draw a lot of power; therefore you need a quality motherboard with a very good VRM.

Yes haha. The exact motherboard in the description (M5A78L-M/USB3) With the way my CPU is behaving with the drops down to 2919MHz (or something similar) is this a sign that the motherboard is the part to blame or could it be something different? ive seen a few people say that their CPU dropped to 1400MHz which is different to mine for some reason? If i were to upgrade i was looking at the "Asus M5A97 EVO R2.0" which people have said is good for FX chips. But dont want to do this and then find out it being something else as this will be a fairly costly upgrade comparing to how much i spent on the PC in the first place. Again thank you very much for the reply though.

 

[GhislainG]

What CPU do you have that required you to disable 2 cores and AMD Turbo Core? You have a cheap motherboard (4+1 phase VRM with no heat sink), but it could also be the cooler that isn't good enough or isn't blowing over the VRM MOSFETs to cool them. It's difficult to determine the source of the issue without knowing the thermal margins in AMD Overdrive when the frequency drops. Are they above 10°C? You're not the only one having similar issues because you didn't spend enough money up front to get high quality parts. The Asus M5A97 EVO R2.0 is a good motherboard (6+2 phase VRM with a heat sink), but you need to make sure the cooler is good enough for your CPU. Why consider a motherboard released 5 years ago instead of the new ASUS 970 PRO GAMING/AURA?