[SOLVED] What is 8700k stock core voltage?

[mjbn1977]

When we are overclocking our CPUs we basically operate them outside the manufacturers specifications. I know what Intel's specifications are in regard to the clock speeds for the 8700k. But what would be the specification for the core voltage? I couldn't find any info on ark.intel.com.

I am just curious. Thanks.

 

[ingtar33]

modern CPUs don't really have a "default" vcore. Their vcore is decided by the chip itself.

 

[mjbn1977]

modern CPUs don't really have a "default" vcore. Their vcore is decided by the chip itself.

Ok, but is there a maximum? If I overclock to 4.8Ghz on all cores and leave Vcore to auto, it will usually put the vcore at V1.24 at full load.

 

[nikoli707]

maximum safe? most will agree you shouldn't go past 1.40v on the core unless you have delid with liquid metal and very good cooling. your dark rock 3 isn't enough on the cooling end, and your msi carbon pro is going to run into vrm/mosfet heat issues as well.

 

[marksavio]

+1 on @nikoli
When we are overclocking our CPUs we basically operate them outside the manufacturers specifications
with your opening statement i wouldve expectd you guys to know already some idea of what vcore value to put in

 

[mjbn1977]

maximum safe? most will agree you shouldn't go past 1.40v on the core unless you have delid with liquid metal and very good cooling. your dark rock 3 isn't enough on the cooling end, and your msi carbon pro is going to run into vrm/mosfet heat issues as well.

1. Maximum safe was not my question. My question was with what core voltages a 8700k @stock operates in and what is considered "normal" stock. I mostly asked out of curiosity.
2. Why wouldn't be the Dark Rock Pro 3 enough on the cooling end? with an Corsair H110i you can cool maybe ~5 degress celsius more, but than the case sounds like a boing 747 at takeoff. Maybe with custom loops you can be much cooler but I don't plan to break overclocking world records. my Dark Rock Pro 3 runs plenty cool at 4.8 GHz (will stay under 85C with prime95 running with AVX). Yes, if I go to 5 Ghz I have to set an AVX offset (hey, but even they guys from silicon lottery do that!)

 

[nikoli707]

maximum safe? most will agree you shouldn't go past 1.40v on the core unless you have delid with liquid metal and very good cooling. your dark rock 3 isn't enough on the cooling end, and your msi carbon pro is going to run into vrm/mosfet heat issues as well.

1. Maximum safe was not my question. My question was with what core voltages a 8700k @stock operates in and what is considered "normal" stock. I mostly asked out of curiosity.
2. Why wouldn't be the Dark Rock Pro 3 enough on the cooling end? with an Corsair H110i you can cool maybe ~5 degress celsius more, but than the case sounds like a boing 747 at takeoff. Maybe with custom loops you can be much cooler but I don't plan to break overclocking world records. my Dark Rock Pro 3 runs plenty cool at 4.8 GHz (will stay under 85C with prime95 running with AVX). Yes, if I go to 5 Ghz I have to set an AVX offset (hey, but even they guys from silicon lottery do that!)

if you are asking stock with pirme95 load you might see anywhere from 1.15v to 1.20v depending on the cpu lottery. though most are going to end up in a tight range, there are probably a few processors that can run outside that range depending on the silicon.

otherwise its normal vcore stepping range was determined by a bunch of factors at the factory, each cpu will be different. dont interpret that as meaning if the cpu1 runs at a lower stock vcore than cpu2 then cpu1 must overclock better... there are more factors than that. generally intel saves the cpus that end up with the lowest vcore for laptop and xeon so they can further undervolt and underclock to get tdp/wattage down or for higher demand stability reasons.

your dark rock 3 is an excellent air cooler, i didnt mean to say it wasn't. i was just mentioning it really isn't up to the task of going over the max safe vcore. since you posted in the overclocking sub and i wasn't exactly sure what you were asking put "maximum safe" with a question mark. and 4.8ghz is plenty of cpu horsepower... 5.0ghz will really only get you about 4% more performance which is pretty much negligible in most tasks, especially gaming. though you can likely tinker a little bit with llc and avx offset and get a little higher while either maintaining the same temps or possibly a tiny bit lower, but it will take some time and overclocking patience.

 

[mjbn1977]

maximum safe? most will agree you shouldn't go past 1.40v on the core unless you have delid with liquid metal and very good cooling. your dark rock 3 isn't enough on the cooling end, and your msi carbon pro is going to run into vrm/mosfet heat issues as well.

1. Maximum safe was not my question. My question was with what core voltages a 8700k @stock operates in and what is considered "normal" stock. I mostly asked out of curiosity.
2. Why wouldn't be the Dark Rock Pro 3 enough on the cooling end? with an Corsair H110i you can cool maybe ~5 degress celsius more, but than the case sounds like a boing 747 at takeoff. Maybe with custom loops you can be much cooler but I don't plan to break overclocking world records. my Dark Rock Pro 3 runs plenty cool at 4.8 GHz (will stay under 85C with prime95 running with AVX). Yes, if I go to 5 Ghz I have to set an AVX offset (hey, but even they guys from silicon lottery do that!)

if you are asking stock with pirme95 load you might see anywhere from 1.15v to 1.20v depending on the cpu lottery. though most are going to end up in a tight range, there are probably a few processors that can run outside that range depending on the silicon.

otherwise its normal vcore stepping range was determined by a bunch of factors at the factory, each cpu will be different. dont interpret that as meaning if the cpu1 runs at a lower stock vcore than cpu2 then cpu1 must overclock better... there are more factors than that. generally intel saves the cpus that end up with the lowest vcore for laptop and xeon so they can further undervolt and underclock to get tdp/wattage down or for higher demand stability reasons.

your dark rock 3 is an excellent air cooler, i didnt mean to say it wasn't. i was just mentioning it really isn't up to the task of going over the max safe vcore. since you posted in the overclocking sub and i wasn't exactly sure what you were asking put "maximum safe" with a question mark. and 4.8ghz is plenty of cpu horsepower... 5.0ghz will really only get you about 4% more performance which is pretty much negligible in most tasks, especially gaming. though you can likely tinker a little bit with llc and avx offset and get a little higher while either maintaining the same temps or possibly a tiny bit lower, but it will take some time and overclocking patience.

Actually, I put the CPU back on stock and ran a few benchmarks. Seems like will go up to 1.245 during most demanding situations (prime95 with AVX).

Yeah, I will make 4.8Ghz my 24/7 overclock. I will play around a little bit with 5Ghz just for fun. 5 is just such a nice round number. But temps will be to high for a 24/7 (I did't delid, not sure if I will) so I just use it for a little bench marking and stuff.

At 4.8Ghz @ around the 1.25 the temps seem fine. Below 85C while running prime95 with AVX (no offset).

 

[nikoli707]

1.25v is far into the safe zone, you have lot of voltage headroom. but like i said, a 4% performance increase to 5.0ghz in the end doesn't really make all that much of a difference.... buuut it is a very nice round number. run prime95 26.6 (non avx) and report your temps. i think you have more cooling headroom in your dark rock.

 

[mjbn1977]

with prime95 26.6 the temps are absolutely fine. but as soon as I do prime95 with AVX and no offset on more than 1.3V it hits mid to high 90Cs right away (one core even hits 100C). So I usually stop it right away. When I run prime95 with AVX at 4.8Ghz on ~1.25V the temps are around 85C.

 

[nikoli707]

i would run a higher avx offset then. what vcore and temps are you getting with non avx for your overclock?

 

[dlaynd]

Maybe not on the subject but as some people already started talking about temps and OCs. So here are my few cents.

I did delid/relid on my i7-8700k. Replaced original paste with Coolaboratory Liquid Ultra and put same stuff between Arctic Freezer 240 and heatspreader.

So my results with prime95 (AVX).

@4.9GHz 1.30V 22C ambient: max core temp 59C (37C delta which is great) 9.2% performance increase compared to stock
@5Ghz 1.36V 22.5 ambient: max core temp 68C (45.5C delta) 11% performance increase compared to stock

I went with 4.9GHz because 1.8% performance gain with +9C probably not worth it.

So delid/relid was definitely a success. Next will do my i7-7700K which is not great right now with temps... Plus I got my hands on even better thermal solution by Thermal Grizzly: Conductonaut.

If anyone interested I can do delid/relid as a service for a reasonable price. Of course it will be on your own risk bc even though not a hard process there are always some risks associated with this process.

 

[chrysalis]

Depends on the motherboard, on my asrock the default is 1.28v

I wouldnt go higher than 1.3v for non AVX loads, and 1.32V for AVX loads. I know people claim that voltage doesnt matter as long as temps are low, but higher voltage accelerates degradation.

I think anything even close to 1.4v is dangerous for 24/7 use.

 

[Maxsupertweaker]

I am pretty much in the same range as the others who have i7 8700K and overclocked them. I could OC higher and easily reach 5.1 "IF" I wanted to modify my case and put a dual or triple fan AIO CPU cooler into the mix.

However, I have always liked the Noctua D15 Air Cooler and how incredibly quiet and effective it is. I use both fans, one on the end and one in the middle of the ginormous D15. I am also able to fit low profile 32GB of Corsair 3000Mhz RAM. Here are my specs.

https://valid.x86.fr/g1a479

https://www.userbenchmark.com/UserRun/11941055

 

[vMax]

Same as Dlaynd with a delidded 8700K with 4.9GHz at 1.278v though it requires more than 1.35v for 5GHz which I am not happy to go to......I think 1.2v is practically base.

 

[Maxsupertweaker]

Same as Dlaynd with a delidded 8700K with 4.9GHz at 1.278v though it requires more than 1.35v for 5GHz which I am not happy to go to......I think 1.2v is practically base.

If I used a large CLC I would easily reach 51 but why bother? The fact that boost speed default is 4.5 I think using the AI Tweaker in UEFI BIOS then tweaking the Memory up from 2800, to 3000ish and reaching 4.9 (400Mhz increase) is plenty fast. I have to say the Noctua D15 is so quiet with dual fans between the heatsinks does a fantastic job. No more Closed Looped Coolers for me and I've used them for 12 years.