Overclocked i7-8700k seems to getting really hot when video rendering

Hi,

I not too long ago received a custom built overclocked i7-8700k from PC Specialist but I have noticed a possible issue. I have a Corsair Crystal Series 460X Case, Corsair H100i V2 Hydra Cooler, 32GB Ram DDR4 3000Mhz, Gigabyte Ultra Gaming, 8GB Nvidia Geforce GTX 1080 and a 550w Gold Standard Corsair PSU

Recently I've been doing some video rendering using Vegas Movie Studio 14. The project I was rendering was around 12 minutes in length and was set to a resolution of 1920x1080 60fps. When I started the render using the CPU it estimated the complete time to be around 10 minutes which I thought was great. But half way through my Corsair H100i V2 went in to overdrive and sounded like a jet engine.

I checked the task manager and it showed that Vegas was using pretty much 100% of the CPU and the column was turning red. I thought that this didn't seem too right as my previous computer which was around 8 years old never made this much noise when rendering.

I downloaded CoreTemp to check the temperature of the CPU and it was ranging from 85-95C which again didn't seem right considering this is a new build doing a task it shouldn't have any trouble processing. I also download another app which gave temperature readings and when I did the render again a pop-up appeared saying that the temperature has exceeded 85C and prolonged use at this temperature would shorten the lifespan of the CPU.


I would like to ask if this type of behaviour is normal or are there any specific tests I can perform such as benchmarks to figure out if there really is an issue or if it's all in my head? This is the first overclocked PC I've ever owned or used so please excuse my ignorance.

Any help you can give would be very much appreciated. I would hate to bother PC Specialist with a non-issue.

Thanks for your help.

Maybe worth installing Corsair Link which will tell you temps, fan speeds and most importantly, pump speeds:

http://downloads.corsair.com/download?item=Files/Corsair-Link/Corsair-LINK-Installer-v4.9.7.35.zip

The pump can sometimes fail which would cause these kinds of symptoms.

There’s also the possibility a bubble has formed on the pasting and a repaste could fix it, but pump is the first thing to check.

I’d agree those temps are too high even at full throttle. I’d expect max temps of 75c

While I'm not familiar with Vegas, rendering / video encoding is generally one of the most demanding things you can ask a CPU to do, so seeing 100% CPU load is what I'd expect. Also, high CPU load isn't inherently a problem. After all that's what powerful CPUs are for...

So it's possible the high load is 100% normal. If it's not, then that's highly unlikely to be due to a hardware issue.

The temps do sound quite high, especially in the 90s.

In addition to what Spydertracks said above it's always possible PCS gave the CPU a bit too much voltage (or that through bad silicon lottery luck, yours needs that much voltage to keep the OC). You could use something like CPU-Z to see what voltage it's running when at 100% load. But I'd check the above before looking at this.

Thanks for your response. I was previously using the Corsair Utility (Beta) to manage the H100i V2 but I re-installed Corsair Link as you have suggested.

I tried to run the exact same settings as the first time I noticed this issue but not sure I was able to completely recreate it nor am I sure it ran has hot as it did that first time. However please find below links to some snapshots of the different stages of the rendering process along with the temperature of everything. I noticed that Temp #5 of the Gigabyte Ultra Gaming was running extremely high at over 100C. That is an issue right?

Lastly the H100i V2 was set to balanced in regards to the fans and quiet for the pump. I changed both of them to performance during the test but the heat output barely changed was still averaging over 80C. I also ran the test with a video at a resolution of 720 at 30fps and the results were unfortunately the same.



Same images as above
https://ibb.co/mMr7cy
https://ibb.co/mNcPPd
https://ibb.co/cbyW4d
https://ibb.co/mkaB4d
https://ibb.co/iZB7cy

I can't get into this at the moment, but before I forget, wanted to ask if the rendering is using AVX?

AVX loads can cause sky high temps with modern Intel CPUs such that people often use different overclocking settings for those. I think I've seen this discussed in Asus overclocking guides.

Sorry that's not more than breadcrumbs, may try to look in more detail later, but could be worth looking into.

Sorry, I do not know what AVX is but I do not believe I am using it. The image below shows the settings I used to render this particular project. Thanks again

If the thing around 100 degrees is VRM temp, this could be quite safe.

Maybe Spyder or someone will be able to go over the pump/ fan speeds in more detail later on. If that's Vcore, then the voltage seems alright. Though PCS could have overestimated the voltage needed for a given chip. i.e. your CPU might run at its overclocked frequencies under a lower voltage, which should reduce temps.

You could try using an AVX offset of 2 too: https://overclocking.guide/gigabyte-z370-overclocking-coffee-lake/

Make sure to back up your BIOS settings before changing any values if you go down that road

Looks like poor pasting to me. The delta between the cooler and the CPU is almost 50°C, I can't imagine that being anywhere near right. The cooler keeping the liquid at 40C suggests that the cooler is working very well, it's just not being conducted correctly. There has been a history of poor pasting from PCS IMO. I personally had my system in 3 times and had to re-paste it myself 3 times. It's an area that could do with more focused training IMO.

I tend to agree with The_Scotster, in that a repaste may be required.

The pump speeds are good and the fans working well. Even with the overclock and at full load, temps shouldn’t reach past about 75c imho.

Although I’m not familiar with AVX if that has an impact on temps under rendering?

I ran Prime95 on a 4790k @ 4.6GHz once and forgot to disable AVX / use an older version of Prime without it. 100 degrees instantly. Oops. Without AVX, high 70s/low 80s at most after a prolonged stress test. It's very common for OCs to use an AVX offset now I believe, where you're likely to run into that.

The_Scotster's suggestion sounds very sensible.

Oussebon said:

I ran Prime95 on a 4790k @ 4.6GHz once and forgot to disable AVX / use an older version of Prime without it. 100 degrees instantly. Oops. Without AVX, high 70s/low 80s at most after a prolonged stress test. It's very common for OCs to use an AVX offset now I believe, where you're likely to run into that.

The_Scotster's suggestion sounds very sensible.

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Thank you all for your reply. I am still not sure what AVX is, but should I follow your instructions above and change the value in the BIOS to 2? I should just follow the instructions via the link below:
https://overclocking.guide/gigabyte-z370-overclocking-coffee-lake/

I had a quick look online and I can't seem to find any information about Vegas Movie Studio 14 using AVX when it renders a video.

The_Scotster
Looks like poor pasting to me. The delta between the cooler and the CPU is almost 50°C, I can't imagine that being anywhere near right. The cooler keeping the liquid at 40C suggests that the cooler is working very well, it's just not being conducted correctly. There has been a history of poor pasting from PCS IMO. I personally had my system in 3 times and had to re-paste it myself 3 times. It's an area that could do with more focused training IMO.

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Thanks for your advice, I will try out your suggestion to see if that makes any difference.

SpyderTracks
I tend to agree with The_Scotster, in that a repaste may be required.

The pump speeds are good and the fans working well. Even with the overclock and at full load, temps shouldn’t reach past about 75c imho.

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Thanks for confirming that the cooler is working as it should. Do you know if there is a way to confirm what areas each of the temperature readings on the motherboard are? How would I know Temp #5 is the VRM temperature? Is there any way to confirm which each of the Temp 1, 2, 3, 4, 5 and 6 are on the motherboard? Thanks again for your help.

dgrey6891 said:

... I am still not sure what AVX is...

Click to expand...

https://en.wikipedia.org/wiki/Advanced_Vector_Extensions.

This was new to me too but all the new AVX instructions listed there operate on internal CPU registers mostly and that means they can run at maximum CPU speed with no waiting for caches and the like. That's probably why they drive the CPU so hard and raise the temps so fast.

So I should change the values of the AVX in the BIOS? I will assume lower is better?

In your position, I would set an AVX offset of 2 as described in the gigabyte overclocking guide and see if this affects temperatures. If nothing else, it may answer whether AVX is being used.

Though bear in mind I've not dealt with this personally, it's just the first thing that comes to mind when someone mentions high temps and video rendering.

So that's not a substitute for what the others in this thread have said

Well right now changing the settings in the BIOS doesn't require me to buy thermal paste or a cleaner. But should this not work I'll have a look at the CPU to see if the paste was applied poorly. Thanks again.

I had a quick look under the hood and noticed that there seems to be a bit too much thermal paste applied. But as I am still new to this, would you say from the pictures below this has been applied poorly? Even right now, I am not doing anything with the PC but I have noticed via Corsair Link that the CPU temp shot up to 55-60C on a couple of the cores randomly. I also changed the AVX setting in the BIOS to a value of 2 but still when I rendered the same project the temperature shout up to 80-86C and higher as soon as the render started. What are your thoughts? Thanks again

dgrey6891 said:

I had a quick look under the hood and noticed that there seems to be a bit too much thermal paste applied. But as I am still new to this, would you say from the pictures below this has been applied poorly? Even right now, I am not doing anything with the PC but I have noticed via Corsair Link that the CPU temp shot up to 55-60C on a couple of the cores. What are your thoughts? Thanks again

View attachment 11739 View attachment 11740

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If you’ve removed the heat sink you’ll need to remove the current paste with isopropyl alcohol and apply some new stuff, you can’t reapply the heat sink once it’s been removed without the temps skyrocketing. I wouldn’t use the pc until you reapply the paste.

SpyderTracks said:

If you’ve removed the heat sink you’ll need to remove the current paste with isopropyl alcohol and apply some new stuff, you can’t reapply the heat sink once it’s been removed without the temps skyrocketing. I wouldn’t use the pc until you reapply the paste.

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Ok, thanks for the info SpyderTracks. Will order some isopropyl alcohol and new thermal paste to sort it out. The idle temperatures are ranging from 33-46, but this is what it was generally before I had a look funnily enough.

Even right now, I am not doing anything with the PC but I have noticed via Corsair Link that the CPU temp shot up to 55-60C on a couple of the cores.

Click to expand...

So if you're running the PC after taking those photos, did you clean off the thermal paste, reapply fresh paste, and then reattach the cooler?

Or just take the cooler off, look at it, and screw it back on?

If the latter, you should avoid doing anything demanding - ideally anything at all - with the PC (i.e. leave it switched off) until you can repaste it. Taking the heatsink off and just putting it back on with the same paste will have introduced air in there and will significantly impair the cooling.

Edit: Too slow

Oussebon said:

So if you're running the PC after taking those photos, did you clean off the thermal paste, reapply fresh paste, and then reattach the cooler?

Or just take the cooler off, look at it, and screw it back on?

If the latter, you should avoid doing anything demanding - ideally anything at all - with the PC (i.e. leave it switched off) until you can repaste it. Taking the heatsink off and just putting it back on with the same paste will have introduced air in there and will significantly impair the cooling.

Edit: Too slow

Click to expand...

Unfortunately I did the latter so I will need to reapply. Do you have any recommendations on which thermal paste/cleaner I should buy? Thank you.