How likely for 8700k to run 4.7Ghz all cores @ stock voltage?

[cmdrdredd]

I have an 8700k arriving tomorrow and once I get everything setup I want to get a bit of an overclock out of it. My motherboard will be an Asus Maximus X Hero and from what I've read it's about as easy as manually setting the ratio to 47 and setting the voltage manually. I do have one additional question though, what is the best way to set the voltage so that when it downclocks at idle it will also drop voltages? Do I use an offset or will manually setting the voltage to 1.25v or whatever is stable also allow it to drop voltage at idle?

Been a long while since I've built a new system for myself and need to re-learn.

 

[Muadib]

Do you plan to delid? Your temps will drop, and you will hit 5 with no problem. I have a different board than you, but I see no problem with the Hero. My voltage doesn't drop, but with the CPU temps in the 60s it's no issue.

 

[cmdrdredd]

Do you plan to delid? Your temps will drop, and you will hit 5 with no problem. I have a different board than you, but I see no problem with the Hero. My voltage doesn't drop, but with the CPU temps in the 60s it's no issue.

No I won't delid and don't care about 5Ghz. I don't benchmark and chase numbers and think 4.7 is more than enough speed. I gather from my cursory attempt at researching this that 4.7Ghz is pretty easy and 5Ghz is either very hard to control temps due to voltage or delidding as you mentioned is required, perhaps even custom water cooling required for some chips.

So basically what did you do? Set voltage manually and adjust the multiplier?

 

[Kenmitch]

If you want voltage to throttle down you'll have to use an offset.

 

[cmdrdredd]

If you want voltage to throttle down you'll have to use an offset.

It been a while but I think that’s how it worked on my 3570k as well.

So let me see if I understand how this should go.

I set manual overclock, turn off Multicore Enhancement, lock the turbo to all cores 47(for 4.7ghz), use load line calibration on high to counter vdroop and then adjust the voltage offset + or - until I get to where it’s stable at full load with good temps. Then I can either leave it if temps are good or drop it more and test again until it is not stable. That about right?

 

[Midwayman]

47x all core should be 100% or close to it. Its very conservative for the 8700k.

 

[IEC]

I have an 8700k arriving tomorrow and once I get everything setup I want to get a bit of an overclock out of it. My motherboard will be an Asus Maximus X Hero and from what I've read it's about as easy as manually setting the ratio to 47 and setting the voltage manually. I do have one additional question though, what is the best way to set the voltage so that when it downclocks at idle it will also drop voltages? Do I use an offset or will manually setting the voltage to 1.25v or whatever is stable also allow it to drop voltage at idle?

Been a long while since I've built a new system for myself and need to re-learn.

I use a -50mV vCore offset for a 4700MHz all-core OC (no AVX offset). This is 100% stable including validated quorum 2 BOINC results on LLC1. YMMV on undervolting.

 

[Kenmitch]

It been a while but I think that’s how it worked on my 3570k as well.

So let me see if I understand how this should go.

I set manual overclock, turn off Multicore Enhancement, lock the turbo to all cores 47(for 4.7ghz), use load line calibration on high to counter vdroop and then adjust the voltage offset + or - until I get to where it’s stable at full load with good temps. Then I can either leave it if temps are good or drop it more and test again until it is not stable. That about right?

I'm not really into desktop rigs and overclocking anymore. The last one I played around with was a 4790k.

Wasn't much involved as far as I remember at least.

Set vcore to normal, set the offset to 0.000v. Auto vcore is usually to generous at higher multipliers.
Changed all the load turbos to the desired overclock
Save and exit, reboot into uefi and took a look at vcore to see if I thought it was OK to proceed.
You'll have to play around with the offset. Might need to go in the - or + to get vcore down or to stabilize the overclock.
Really not much involved unless you want to nudge the chip beyond it's comfort zone.
You'll probably be thermally limited before you have to do much tweaking anyways.

 

[cmdrdredd]

47x all core should be 100% or close to it. Its very conservative for the 8700k.

Yeah I don’t need more than that. I’ve been running my 3570k at 4.5ghz since I built it and I k ow that a 8700k at even 4.3ghz is going to likely be faster than what I have now so 4.7 or 4.8 even is plenty.

 

[EXCellR8]

What made you go with the Maximus over the Taichi?

 

[cmdrdredd]

What made you go with the Maximus over the Taichi?

Past experience with ASUS boards and I had read some forum posts about problems with the Asrock boards accepting voltage changes which to be honest may be fixed with new firmware I don’t know.

 

[EXCellR8]

Fair enough.

 

[cmdrdredd]

Having problems with voltage spikes going crazy when trying to use offset or adaptive voltage so I just set it manually.

What is the trick to AVX stability? Trying to run prime95 and get errors quickly on one thread. When I do anything without avx it can run continuously without issue. Should I set an avx offset to like 3 to let the chip clock down even though I’m only at 4.7? I can’t get avx stable without pushing extra voltage and getting thermals that are too high.

 

[epsilon84]

AVX is extremely taxing on the CPU and also results in a much lower 'stable' threshold, hence the offset option in the BIOS.

Unless you use AVX enabled software extensively, I would put an offset of -2 or -3 and call it a day. Your overclock is most likely stable at 4.7GHz on non AVX workloads, I don't see the point in pumping extra voltages and heat just to be 'AVX stable'.

 

[IEC]

Having problems with voltage spikes going crazy when trying to use offset or adaptive voltage so I just set it manually.

What is the trick to AVX stability? Trying to run prime95 and get errors quickly on one thread. When I do anything without avx it can run continuously without issue. Should I set an avx offset to like 3 to let the chip clock down even though I’m only at 4.7? I can’t get avx stable without pushing extra voltage and getting thermals that are too high.

What LLC setting are you using? AVX loads require more power and your vcore could be drooping too much under load to be stable. Use either the best or 2nd best LLC setting to reduce vdroop and see if that results in AVX stability.

Otherwise use a -2 offset and call it a day.

Mine requires no AVX offset at 4.7GHz -50mV vcore offset, but I suspect I just got a "good" sample.

 

[cmdrdredd]

What LLC setting are you using? AVX loads require more power and your vcore could be drooping too much under load to be stable. Use either the best or 2nd best LLC setting to reduce vdroop and see if that results in AVX stability.

Otherwise use a -2 offset and call it a day.

Mine requires no AVX offset at 4.7GHz -50mV vcore offset, but I suspect I just got a "good" sample.

LLC is at 6(max is 7) and I was stable at right around 1.28v for everything including AVX enabled OCCT runs and realbench. It’s just prime95 small fft that throws me fits quickly. I could probably get down to 1.26v or lower if I experiment a bit but my temps from everything except prime95 is below 80c. Even prime95 with SSE instead of AVX was stable and within safe temps.

Offset gave me massive overshoot and I saw numbers around 1.5v right after startup before I did anything. Needless to say I shut it down and cleared cmos for that.

So currently I sit at 1.28v, 4.7ghz, LLC 6. I suspect when I saw errors with prime95 avx it was simply too taxing for my chip at 4.7ghz and I could get away with my current overclock if I drop the avx ratio some. I may even be able to do that at lower voltage. Like I said though, temps are good.

 

[IRobot23]

Maybe you should be a bit more careful with TEMPs/voltage #degradation. Delid you CPU.

 

[cmdrdredd]

Maybe you should be a bit more careful with TEMPs/voltage #degradation. Delid you CPU.

Firstly temps are fine. Below 80c is very good for 6 cores and 12 threads at full load. Second, Voltage is well within safe limits for the chip too. I'm at 1.28v at max during full load. No need to delid unless you're chasing over 5Ghz clock speeds. I'm not.

If you even followed the thread you'd see that I was specifically having trouble getting stable at 4.7Ghz with an AVX instruction set stress test at which is known to ramp up the thermals and push the CPU to draw more current. Every CPU is different. I didn't win the so called "silicone lottery" and have to settle for 4.7Ghz on all cores without AVX and 4.5Ghz on all cores(after testing) with AVX. This is not bad at all to me.