8700K Throttles at 81 C

[Spikkel]

Hi, I'm trying to see if my current setup is effective:

8700K (not overclocked), air-cooler with push-pull.

Asus multicore enhancement set to Auto.

 

But I noticed during stress testing with prime95 (small FFT) that the CPU clock speed drops from 4295 down to 3796 as soon as I hit 81C (real temp). Why? T-max at a 100??

 

Also... any ideas how I can check to see if I'm getting 4700 on a single core? All the tests I tried seems to use multicores and then the CPU-boost limits to 4295...

[Firewrath9]

cinebench single threaded.

what air cooler?

[Jihakuz]

You can see what each core is running at if you right click on CPU-Z when you run a benchmark. And what cooler?

[.Apex.]

33 minutes ago, Spikkel said:

Hi, I'm trying to see if my current setup is effective:

8700K (not overclocked), air-cooler with push-pull.

Asus multicore enhancement set to Auto.

 

But I noticed during stress testing with prime95 (small FFT) that the CPU clock speed drops from 4295 down to 3796 as soon as I hit 81C (real temp). Why? T-max at a 100??

 

Also... any ideas how I can check to see if I'm getting 4700 on a single core? All the tests I tried seems to use multicores and then the CPU-boost limits to 4295...

there seems to be a power limit, my CPU reaches 4.3Ghz stable on all cores with no issues, and 4.4 - 4.7Ghz depending on how many cores are being used.

 

what's your motherboard? could be VRM's overheating and throttling.

[Spikkel]

3 hours ago, Firewrath9 said:

cinebench single threaded.

what air cooler?

Cinebech single threaded - it kind of works... I'm getting up to 4595 Mhz now (avg 4495) but it seems (in task manager) that the load gets thrown around between cores.

Is this maybe window's doing?

Cooller is a Coolermaster hyper 612 v2. Fan replaced with 2x Corsair pressure optimized 120mm performance edition 

 

2 hours ago, syn2112 said:

there seems to be a power limit, my CPU reaches 4.3Ghz stable on all cores with no issues, and 4.4 - 4.7Ghz depending on how many cores are being used.

what's your motherboard? could be VRM's overheating and throttling.

Motherboard is a Z370 A-Prime. Good airflow in case and relatively low ambient (we're having a cool spring in RSA). How do I monitor for CPU power limit?

[.Apex.]

3 minutes ago, Spikkel said:

Motherboard is a Z370 A-Prime. Good airflow in case and relatively low ambient (we're having a cool spring in RSA). How do I monitor for CPU power limit?

well i also have the Z370-A Prime... did you try resetting your BIOS? maybe you changed a setting there by mistake

also try updating your BIOS, might be a glitch

 

it shouldn't throttle at 81C, unless real temp is reporting wrong temperatures (ironic)

[Spikkel]

1 minute ago, syn2112 said:

well i also have the Z370-A Prime... did you try resetting your BIOS? maybe you changed a setting there by mistake

also try updating your BIOS, might be a glitch

 

it shouldn't throttle at 81C, unless real temp is reporting wrong temperatures (ironic)

Yes, I just updated too ver. 1002 from 0606. No change. Also reset settings, only enabled XMP which in turn also sets MCE and CPU core ratio to AUTO.

used real temp and confirmed with MSI afterburner. 

[PeterPorker3]

1 hour ago, Spikkel said:

Hi, I'm trying to see if my current setup is effective:

8700K (not overclocked), air-cooler with push-pull.

Asus multicore enhancement set to Auto.

 

But I noticed during stress testing with prime95 (small FFT) that the CPU clock speed drops from 4295 down to 3796 as soon as I hit 81C (real temp). Why? T-max at a 100??

 

Also... any ideas how I can check to see if I'm getting 4700 on a single core? All the tests I tried seems to use multicores and then the CPU-boost limits to 4295...

Maybe its a motherboard VRM issue? The ASUS PRIME series is known for having a very weak VRM. You could try putting a fan directly on the VRM heatsink and see if that helps. Also, try using a program called throttlestop. This program allows you to disable throttling on most systems, but it will not disable auto shutdown: https://www.techpowerup.com/download/techpowerup-throttlestop/ NOTE: This is just for trobbleshooting porpouses, do not use this as a long term solution, especialy if the VRM is overheating.

[Spikkel]

16 minutes ago, MineParker101 said:

Maybe its a motherboard VRM issue? The ASUS PRIME series is known for having a very weak VRM. You could try putting a fan directly on the VRM heatsink and see if that helps. Also, try using a program called throttlestop. This program allows you to disable throttling on most systems, but it will not disable auto shutdown: https://www.techpowerup.com/download/techpowerup-throttlestop/ NOTE: This is just for trobbleshooting porpouses, do not use this as a long term solution, especialy if the VRM is overheating.

Oooh, thanx for the software suggestion, but I think I'll save it for a last resort - sounds a bit risky. I just installed that tiny bracket + fan (intended for the VRM's that comes with the MB. No change.

[PeterPorker3]

Just now, Spikkel said:

Oooh, thanx for the software suggestion, but I think I'll save it for a last resort - sounds a bit risky. I just installed that tiny bracket + fan (intended for the VRM's that comes with the MB. No change.

You could also install the intel extreme tuning utility. This could tell you if your motherboard is throttling from over current or over temp and other useful information. 

[Spikkel]

20 minutes ago, MineParker101 said:

You could also install the intel extreme tuning utility. This could tell you if your motherboard is throttling from over current or over temp and other useful information. 

SPOT ON!!! Intel extreme tuning utility indicates a power limit. So if I'm getting this... is my VRM's still too hot, causing a power limit? Or is my Thermaltake 700w PSU too small (its old), only other power hungry component is a non-overclocked MSI gaming x 1070.

[AntiTrust]

4 minutes ago, Spikkel said:

SPOT ON!!! Intel extreme tuning utility indicates a power limit. So if I'm getting this... is my VRM's still too hot, causing a power limit? Or is my Thermaltake 700w PSU too small (its old), only other power hungry component is a non-overclocked MSI gaming x 1070.

something is wrong here. that cpu cooler you have is a monster it really shouldn't be getting anywhere near the 80's on stock. 

 

I would recheck your cooler install and maybe redo thermal paste application with as little as possible. 

[Spikkel]

35 minutes ago, AntiTrust said:

something is wrong here. that cpu cooler you have is a monster it really shouldn't be getting anywhere near the 80's on stock. 

 

I would recheck your cooler install and maybe redo thermal paste application with as little as possible. 

I removed the cooler, thermal paste application looked good - good spread. I cleaned, reapplied, and re-installed the cooler. Issue persists. What bothers me is the fact that I'm getting a power limit at all. Shouldn't I reach a 100 C and thermal throttle without getting a power limit? BTW, the limit is reached only after about 25s of running prime95 on small FFts only. The other stress options doesn't hit the limit.

[airdeano]

some boards have VRM monitoring and limits. HardwareMonitor might have access to that probe (if equipped).

though your CPU is seeing 80°, your mobo VRM could be seeing 115°+

[agazoo]

I this a new CPU? Just bought it? What about MoBo?

[Spikkel]

4 minutes ago, agazoo said:

I this a new CPU? Just bought it? What about MoBo?

Nov 2017.

[Spikkel]

40 minutes ago, airdeano said:

some boards have VRM monitoring and limits. HardwareMonitor might have access to that probe (if equipped).

though your CPU is seeing 80°, your mobo VRM could be seeing 115°+

This one?

https://www.cpuid.com/downloads/hwmonitor/hwmonitor_1.36.exe

[airdeano]

yes

[Spikkel]

9 minutes ago, Spikkel said:

This one?

https://www.cpuid.com/downloads/hwmonitor/hwmonitor_1.36.exe

Does any of these results stand out?

[Spikkel]

Thank you everybody for you contributions I've learnt so much today.

It seems the firmware is behaving like it should:

I noticed in Intel's extreme tuning utility that the default "turbo boost power time window" is 28 seconds. Almost the 25 seconds I mentioned above.

I'll start a new thread on not reaching 4.7 on a single core.

Regards!