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Jhey
Beginner
2,033 Views

8700 non K Turbo TDP issue.

Hi all,

Not sure how to ask these questions but I shall try my best lol, I recently brought an intel i7 8700 non K coupled with an Asus ROG z370-e motherboard but I am having frustrating issues with the CPU throttling massively as soon as I run anything that is CPU intensive for example handbrake video encoding or benchmarking, I am fully aware that the non K models have a lower TDP than the K model but I have seen many other videos of people with the same CPU running it through prolonged benchmarks without any throttling So im left wondering do I have a defective CPU or Motherboard or Bios or even power supply?

I'm currently cooling the cpu with a Kraken x52 AIO which keeps the temps even underload mostly below 70c which is great but thats mostly because it turbos to 4.3ghz for a few seconds then drops down to 3.6ghz for the remainder of any benchmarks etc.

I have linked a video of this issue https://youtu.be/IPNzx2MHLXg here https://youtu.be/IPNzx2MHLXg Intel i7 8700 non K throttling issues Asus z370-e - YouTube It seems to happen from what I can see when the TDP hits over 100Watts ? I know its limited to 65Watts but even the K model goes over its 95W limit .

I shall upload a video of my bios settings shortly so hopefully someone can take a look and see if I have anything wrong in there that would be awsome thanks. Video of standard bios settings https://www.youtube.com/watch?v=eBU8VZDV7Us here https://www.youtube.com/watch?v=eBU8VZDV7Us Asus z370-e ROG strix 1002 bios settings default run through - YouTube

I even tried enabling the XMP profile and the results were hilarious ( Sarscam ) it can be seen https://youtu.be/LAknRUfr9ZE here https://youtu.be/LAknRUfr9ZE Asus z370-e ROG strix Xmp profile 1 3000mhz NO to overclock option - YouTube

Intresting I enabled XMP profile but this time selected YES and this was the result however I am concerned with the voltage increase that doesnt seem to drop when the cpu is Idle at 800mhz min Vcore 1.216v max 1.376v seems a little high..

Video https://www.youtube.com/watch?v=TlbVuORY2kA here https://www.youtube.com/watch?v=TlbVuORY2kA Asus z370-e ROG strix Xmp profile 1 3000mhz YES to overclock - YouTube

I was going to attempt to undervolt my cpu as apparently this is the done thing to do on non K versions but I tried lowering it and used Adaptive -0.25 but all it did was make my voltage go up although I shall be honest there are so many bios settings these days I haven't got a clue what half of them do

I haven't even set my Memory Xmp profile because it asks me if I want to overclock my system, and if i click no it still changes my BCLK to something like 102+ which im unsure if thats safe I presume the BCLK is like the Front side bus of older tech? Also when I enable XMP is also ups the voltage to the CPU ..

Any help or advice on any of this in laymans terms would be greatly appreciated.

Regards

Jay

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3 Replies
MGorb1
New Contributor I
413 Views

This isn't throttling. It is proper Turbo Boost behavior. Max TDP can be "ignored" on many Intel CPUs for about 28 seconds (configurable).

https://ark.intel.com/products/126686/Intel-Core-i7-8700-Processor-12M-Cache-up-to-4_60-GHz i7-8700 has base clock of 3.2GHz. This is a frequency at which CPU is guaranteed to function for a long time with a heavy workload.

When you activated OC profile in BIOS and answered NO then you saw ~2150MHz on all cores while thermal management maintained 65W TDP because there was quite a high voltage (1.28V) which haven't been lowered. That is because power drawn is almost linear to frequency. What means that if CPU working at 4.3GHz frequency takes 119W (includes 12W uncore) of power then if limited to only 65W it will be clocked about (65-12)*(4.4/107) = 2.18GHz. And you got almost exactly that.

When you answered YES then max TDP limit was obviously removed. As a matter of fact if BIOS doesn't lock CPU's MSR where power limit is defined then default 65W value can be removed with tools like ThrottleStop. Maybe you should go that way.

Best way forward would be to not OC CPU but remove TDP limit. Also setting memory clock to 1466MHz and CL to 15. It is strange that when you use XMP profile BIOS also overclocks CPU. That shouldn't be default behavior.

Jhey
Beginner
413 Views

Hiya Gorbush,

Thanks for the reply, and the explanation although im not sure how you got 119Watts from 4.3ghz also what is uncore ? Im not saying you are wrong I was just wondering how u work out 119watts from 4.3ghz etc.

To be honest I'm happy with it behaving the way it was I mostly game occasionally live stream and for the most part it works just fine, I just thought I must have an issue as I've seen many other videos on youtube like this one https://www.youtube.com/watch?v=pno7G0caAWY https://www.youtube.com/watch?v=pno7G0caAWY where they don't seem to have any of these issues and the video i've linked is even running on a fairly cheap cooler.. Unfortunately you can't see his TDP but his voltage is 1.28 why isnt he getting the same throttling?

I have my system setup as the last video XMP overclock YES and it runs at the BOOST speed constantly while using the CPU and downclocks when Idle however the Voltage no longer drops when the CPU is idle and stays around 1.21v when in use its hitting a max of 1.36v is this safe? Also if i was to disable the XMP profile and just set my ram manually etc do I have to set the voltage manually for the ram also?

I've read intels Extreme Tuning Utility (XTU) can also remove the TDP limit.

Regards

Jay

MGorb1
New Contributor I
413 Views

how you got 119Watts from 4.3ghz also what is uncore ?

Small errata: 4.3GHz should be 4.4GHz.

These are data points gathered from your https://youtu.be/LAknRUfr9ZE?t=107 second video when you've just began Cinbench test.

Uncore is part of the CPU package separate from each CPU cores (IA cores). It usually contains memory and I/Os controllers. It has separate clock frequency and operational voltage. Even so it is counted towards processor TDP.

I just thought I must have an issue as I've seen many other videos on youtube like this one https://www.youtube.com/watch%3Fv%3Dpno7G0caAWY https://www.youtube.com/watch?v=pno7G0caAWY

This is similar to your third video but even CPU clock isn't lowered when system is idle. Only CPU voltage dropped a little (from 1.37V to 1.23V). That is an effect of CPU OC with disabled max TDP setting.

I have my system setup as the last video XMP overclock YES and it runs at the BOOST speed constantly while using the CPU and downclocks when Idle however the Voltage no longer drops when the CPU is idle and stays around 1.21v when in use its hitting a max of 1.36v is this safe?

Higher voltage will mean higher power usage. This should also translate to higher temperature and that is certainly responsible for shorter CPU life. I'm not exactly sure if higher voltage while CPU is idle will shorten its life. Probably there will be some impact but very minor.

Also if i was to disable the XMP profile and just set my ram manually etc do I have to set the voltage manually for the ram also?

Yes, certainly. You should change all setting with DRAM in their name which were displayed when you set XMP profile inside BIOS and answered NO. That is basically what you can read from memory modules SPD with tools like CPU-Z.

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