8700k running too hot under load?

Bidley · 30 Jul 2018 at 10:58

I've got my 8700k running at 4.8ghz with 1.248v VCORE, all cores set to 48. It seems stable but I'm getting very high temps under heavy load.

CPU-Z stress test I'm getting 80-82c, Aida64 and Prime95 I'm getting 90-92c. Idle it's 36-39c, gaming it's anything from 58c to 72c (roughly).

I'm running;
i7 8700k
Dark Rock 3 cooler
Asrock Extreme4
EVGA GTX 1080ti SC2

Is this normal/safe?

Hagar · 30 Jul 2018 at 11:54

Probably fairly normal. It may be improved by adding or increasing fans and noise or custom cooling but in recent hot weather I would expect 60C plus on all cores with HT under load.

HoneyBadger · 30 Jul 2018 at 11:54

Sounds normal to me.

Where are you based? UK? What's the ambient room temp?

Bidley · 30 Jul 2018 at 12:00

I'm based in the UK. Ambient room temp (these temps were recorded yesterday and today - much cooler where I am) is 24-26c.

Thing is, the 8700k is supposed to be able to do 4.8ghz all day long. Temps into the 90s under stress with such a reserved OC are a bit high no?

I have 2x intake and 2x exhaust 140mm fans in my Fractal R6. Not sure adding more will help.

Think it's worth reapplying thermal paste? Maybe use something posher than Arctic Silver 5?

eddiew · 30 Jul 2018 at 12:08

If not delidded, that's basically what happens to an 8700K

They hit thermal limits before they hit voltage/frequency walls.

Also which Prime 95? The later versions use AVX instructions and absolutely bake the CPU in the way that nothing real ever will. I believe 26.6 was the last pre-AVX version and is what most people use for stressing.

Bidley · 30 Jul 2018 at 12:17

I fear you're probably right

maybe I read too much into received internet wisdom...

I used Prime95 26.6.

eddiew · 30 Jul 2018 at 13:37

Bidley said:
I fear you're probably right maybe I read too much into received internet wisdom...

I used Prime95 26.6.

5+ without delidding is rare, tbh. You have to win both the silicon lottery and the heatpaste lottery. The volts seem respectable though, if you ever did delid it it would probably have a fair shot at 5.0.

You can also check your VCCIO and VCCSA, since these contribute quite a bit to heat and often get set high by default. I'm running 8 Pack's recommended 1.05 and 1.1 respectively, but the board defaulted them to 1.25, and it's a difference of a good 5-10 degrees on the package!

Bidley · 30 Jul 2018 at 15:58

eddiew said:
5+ without delidding is rare, tbh. You have to win both the silicon lottery and the heatpaste lottery. The volts seem respectable though, if you ever did delid it it would probably have a fair shot at 5.0.

You can also check your VCCIO and VCCSA, since these contribute quite a bit to heat and often get set high by default. I'm running 8 Pack's recommended 1.05 and 1.1 respectively, but the board defaulted them to 1.25, and it's a difference of a good 5-10 degrees on the package!

Jesus, that's worth looking at then! Do you recommend I set them to 1.05 and 1.1 too? Or is it a suck-it-and-see job?

I think I might get some Thermal Grizzly and reseat the cooler, just to rule it out.

Bidley · 30 Jul 2018 at 23:11

Well I just checked my VCCIO and VCCSA. The VCCIO was automatically set to 0.950v, and the VCCSA at 1.250v. I knocked the VCCSA down to 1.000v. Idle temps are 1-2c lower, stress temps are about the same, but during gaming it's not going above 65c. In fact during gaming it averages about 57c, which is a marked improvement. Thanks for that tip eddiew!

eddiew · 31 Jul 2018 at 11:37

Bidley said:
Well I just checked my VCCIO and VCCSA. The VCCIO was automatically set to 0.950v, and the VCCSA at 1.250v. I knocked the VCCSA down to 1.000v. Idle temps are 1-2c lower, stress temps are about the same, but during gaming it's not going above 65c. In fact during gaming it averages about 57c, which is a marked improvement. Thanks for that tip eddiew!

Interesting that gaming dropped a lot more than benchmarks... Although, SA relates to memory controller, and if you're doing small FFTs with Prime it doesn't do much memory access anyway, mostly sits in cache. Games might actually put more through the IMC, so that's where you see it

Might try dropping my IO even more if yours is happy at 0.95! I believe that relates to all the non-memory pin voltages, including PCI-E lanes. Since I'm not messing with anything on that, maybe I've got it higher than it needs to be.

Bidley · 1 Aug 2018 at 12:09

My IO has been at 0.95 for a couple of months, so I would say it's pretty happy!

So what do we think re: the stress temps? Aida64 and Prime95 aren't real-world useages are they (for a gaming PC)? Are these ok to live with, or is getting a bigger cooler - like a Dark Rock Pro4 - going to yield much of a return?

Drollic · 1 Aug 2018 at 12:22

They are slightly high but nothing to be too worried about. Thought about a better cooler?

Bidley · 1 Aug 2018 at 12:29

Drollic said:
They are slightly high but nothing to be too worried about. Thought about a better cooler?

As I said in my last post, is a bigger air cooler going to make a significant difference? Like a Dark Rock Pro 4 or something. I wouldn't be comfortable with a liquid AIO or similar, I've heard far too many horror stories.

Drollic · 1 Aug 2018 at 12:32

Bidley said:
As I said in my last post, is a bigger air cooler going to make a significant difference? Like a Dark Rock Pro 4 or something. I wouldn't be comfortable with a liquid AIO or similar, I've heard far too many horror stories.

If you can stomach the looks of some of them and have no ram clearance issues you could probably save a few degrees. New AIO coolers are much better than years ago, far less problems it seems.

Bidley · 1 Aug 2018 at 12:36

Drollic said:
If you can stomach the looks of some of them and have no ram clearance issues you could probably save a few degrees. New AIO coolers are much better than years ago, far less problems it seems.

I could probably live with a Dark Rock Pro 4. D15 I couldn't live with! I'll look into it.

Robzere31 · 1 Aug 2018 at 12:40

Unless you've built the machine to run prime etc permanently, then I wouldn't worry.
I don't know why people get so wound up about prime temps. It's not as though you use it 24 hours a day.

If gaming temps are 50-70c then I would just be happy & enjoy your gaming.
Temps will probably drop once this spell of hot weather goes as well.

Drollic · 1 Aug 2018 at 12:42

Bidley said:
I could probably live with a Dark Rock Pro 4. D15 I couldn't live with! I'll look into it.

Your gaming temps seem a little low compared with Prime. Have you tested 64 player bf1 to see what it hits? It makes good use of all cores /threads generally and the gpu gets worked well increasing case temps you don't get with Prime. You're probably fine as is as I'm conservative with pushing temps and hardware. 25c room in summer though and if gaming you see 80+ and you're planning to keep long term, I'd probably change cooler.

As an example, I never see above 78c on prime, yet with the gfx card pushed and bf1 maxed on 64 mp I can hit 73c in weather like this.

Bidley · 1 Aug 2018 at 15:03

Robzere31 said:
Unless you've built the machine to run prime etc permanently, then I wouldn't worry.
I don't know why people get so wound up about prime temps. It's not as though you use it 24 hours a day.

If gaming temps are 50-70c then I would just be happy & enjoy your gaming.
Temps will probably drop once this spell of hot weather goes as well.

I tend to agree. Only extreme stress tests give me worrying temperatures.

Drollic said:
Your gaming temps seem a little low compared with Prime. Have you tested 64 player bf1 to see what it hits? It makes good use of all cores /threads generally and the gpu gets worked well increasing case temps you don't get with Prime. You're probably fine as is as I'm conservative with pushing temps and hardware. 25c room in summer though and if gaming you see 80+ and you're planning to keep long term, I'd probably change cooler.

As an example, I never see above 78c on prime, yet with the gfx card pushed and bf1 maxed on 64 mp I can hit 73c in weather like this.

I've been running PUBG, Mafia 3 and GTAV, and the temperatures never go above around 65c-70c, save for the odd spike to 80c for a split second when loading the game. I've also run Guild Wars 2 with character limit at max for a good while, with similar results. The average can be anything from 55c to 65c while gaming (using HWINFO).

I will carry on monitoring though. If getting a cooler only saves me 2-3c I think I might pass. I'm going to try reseating my current cooler with some Kryonaut just to be sure I haven't borked the install.

eddiew · 1 Aug 2018 at 21:11

Without a delid, you're not going to do a whole lot better. You can throw a custom water loop at it, but the problem is the thermal connection twixt die and heatspreader, not heatspreader and cooler block. As long as gaming temps are happy, then I really wouldn't worry. Worst case it will throttle to save itself and you'll notice; but right now your prime temps aren't going to make that happen, so I doubt it ever will.

Chaos666 · 1 Aug 2018 at 21:24

your temps are completely normal ...
don't worry... just enjoy your rig..
if you want lower temps and higher oc -> delid is your only option.