To Delid or Not To Delid? That is the Question.

[Blaylock]

So, I've upgraded my i7-4790k for a new i7-8700k and so far it seems to be a good sample. Below is where I'm at with my OC progress along with the associated voltage requirements and resulting temps. I'm running a custom loop with the following components. I'm happy with the overclock but wondering if I could squeeze more out to make it worth voiding my warranty. I'm averaging about a 6°C difference between cores. What do you say?

[oldtable]CPU Block|EKWB Supremacy EVO Full Copper
Radiator(s)|Swifttech 30mmx360mm
Pump/Res Combo|EKWB D5 Xres (set to 5-Max)
Fans|3x Yate Loon D12SH-12 120mm High Speed[/table]

Stress testing was done using AIDA64 Engineer CPU & FPU tests for 30 minutes. Here are my O.C. Notes.

[oldtable]CPU Mhz|Multi Setting|FSB Setting|vCore|LLC|AVX Offset|Max Package Temp|Max Core (Core#)|Min Core Temp (Core #)|Result
4.3Ghz/4.7Ghz(Stock)|43|100|1.152v|Auto|Auto|58°C|58°C(2&3)|56°C(1,4&5)|Pass
4.7Ghz|47|100|1.300v|1|0|75°C|74°C(2&3)|70°C(5)|Pass
4.9Ghz|49|100|1.300v|1|0|84°C|84°C(2)|78°C(1&5)|Pass
5.0Ghz|50|100|1.300v|1|0|85°C|85°C(2&3)|79°C(5)|Pass
5.1Ghz|51|100|1.300v|4|0|XX°C|XX°C()|XX°C()|Sys Hang
5.1Ghz|51|100|1.300v|1|0|75°C|XX°C()|XX°C()|Sys Hang
5.1Ghz|51|100|1.325v|1|0|89°C|89°C(2)|83°C(1)|Pass
5.2Ghz|52|100|1.325v|1|0|XX°C|XX°C()|XX°C()|Sys Hang
5.2Ghz|52|100|1.350v|1|-1|XX°C|XX°C()|XX°C()|Sys Hang
5.2Ghz|52|100|1.375v|1|-2|94°C|93°C(2)|86°C(1&5)|Test Stopped-Temps
5.2Ghz|52|100|1.365v|1|-1|93°C|93°C(2)|85°C(1)|Test Stopped-Temps
5.2Ghz|52|100|1.355v|1|-1|93°C|93°C(2)|85°C(1)|Test Stopped-Temps[/table]

EDIT:
Additional notes. I do run Handbrake frequently and at the 5.1Ghz setting I'm getting about an average of 80% utilization across all 12 threads and my max temps are about 84°C Package and 83° on core #2.

 

[EarthDog]

Tough call. Those clocks are solid and not sure you are going to get much more out of it with a 10-15C drop (an average). If you want it to run cooler at the top end there, go for it.

LMK if you need the delid machine.

 

[Mr.Scott]

I'd do it just for the extra temp headroom. Clocks are already solid.

 

[caddi daddi]

Blaylock, you know what I'm going to vote.............
A solid 5.1 working clock, I'd tell anybody else to leave good enough alone, but if you are going to chase monster clocks like I am this winter, NUDIFY that puppy!!!!!!!

 

[Alaric]

Depends. How close to your voltage ceiling are you? Do you care if you kill it with volts? If you're close to max vcore I'd leave it alone. If you have a fair amount of vcore headroom, go for it.

 

[Woomack]

I'm not sure if you stopped the test or AIDA64 stopped with error at 5.2GHz and higher voltage. If AIDA64 test stopped then it's because of instability, not temps. This CPU should easily go up to ~100°C, then show throttling and then hang.

I would check what temps you get with SVID enabled and disabled. On my ASUS I see lower voltage and temps under load when SVID is disabled but in idle voltage has to be set much higher (like 1.30V load, 1.35V idle). On the other hand, when it's enabled then I have to keep idle and load voltages higher what causes ~+10°C under load.
Just some brain food so you can check something more and maybe lower temps a bit without delidding

I'm not delidding my chips if I'm planning to use them in my daily/gaming PC and nothing else as I simply can't see the difference between 4.5GHz or anything above that. If you wish to sell this CPU in some time then better don't delid it. If you want to keep the rig for 2 years+ then why not.

My 8086K is scaling about the same up to ~5.2GHz ... problems are starting above that. Half of the cores are overclocking worse to the point that 6 cores at 5.6GHz or 2 cores at 6GHz require the same voltage only to boot without bluescreen. On 9900K it's like 6.2GHz/6.0GHz. At least IMC is good in that 8086K.

 

[mackerel]

Temps do affect stability though. I've had systems that run prime95 like tasks 24/7 happily, until temps get too warm e.g. changing seasons, or dust buildup. Then they start producing compute errors until the temps are lowered somehow. The threshold I'm seeing is around 80C or so, and this may be in part why Intel CPUs appear to have a lot of clock headroom, it has to remain stable at elevated temperatures we don't usually want to run at.

As to what to do, that's difficult choice. I'd only delid if going liquid metal, but don't expect this to buy much more on OC, perhaps 100MHz or so. The reduction in temps is a nice extra. If playing it safe, I'd just stick to 5.0 GHz as a nice round number. Find the lowest stable voltage for that and call it a day.

 

[Blaylock]

I'm not sure if you stopped the test or AIDA64 stopped with error at 5.2GHz and higher voltage. If AIDA64 test stopped then it's because of instability, not temps. This CPU should easily go up to ~100°C, then show throttling and then hang.

I would check what temps you get with SVID enabled and disabled. On my ASUS I see lower voltage and temps under load when SVID is disabled but in idle voltage has to be set much higher (like 1.30V load, 1.35V idle). On the other hand, when it's enabled then I have to keep idle and load voltages higher what causes ~+10°C under load.
Just some brain food so you can check something more and maybe lower temps a bit without delidding

I'm not delidding my chips if I'm planning to use them in my daily/gaming PC and nothing else as I simply can't see the difference between 4.5GHz or anything above that. If you wish to sell this CPU in some time then better don't delid it. If you want to keep the rig for 2 years+ then why not.

My 8086K is scaling about the same up to ~5.2GHz ... problems are starting above that. Half of the cores are overclocking worse to the point that 6 cores at 5.6GHz or 2 cores at 6GHz require the same voltage only to boot without bluescreen. On 9900K it's like 6.2GHz/6.0GHz. At least IMC is good in that 8086K.

Thanks for the input Woomack. I was stopping the test myself as I had a set temperature I didn't want to exceed, 94°C in this case. I know they can go a bit higher but this was my predetermined comfort zone as this will be my 24/7 CPU and not a benching chip. Also, in each of those tests that I stopped, those temps were achieved within the first two minutes of the test.

I will test with SVID enable/disabled. I can't say what it's set to currently as this is a new feature for me so it's set to whatever is default, enabled I'm guessing. I do have a question on this though. How are you setting a higher idle voltage and lower load voltage? I've been just setting the CPU Core/Cache Voltage to a static number. Forgive me, I'm still fairly new to Intel Overclocking.

 

[Alaric]

I don't know what your mobo is, but I left my idle voltage alone and set my offset to .+040v (dynamic). Figuring out the vcore on a brand of mobo I wasn't familiar with while OC'ing a brand of chip I wasn't familiar with was...interesting. I'm still not sure how Gigabyte/Intel figure offset, as negative numbers seem to go the wrong way. I saw 1.65 vcore once, while flying through the air like a guided missile for the "OFF NOW DAMNIT" switch. LOL

 

[Johan45]

Before I cast a vote I'm curious to see how it makes out with the newer P95 crunching away on AVX

 

[Woomack]

I will test with SVID enable/disabled. I can't say what it's set to currently as this is a new feature for me so it's set to whatever is default, enabled I'm guessing. I do have a question on this though. How are you setting a higher idle voltage and lower load voltage? I've been just setting the CPU Core/Cache Voltage to a static number. Forgive me, I'm still fairly new to Intel Overclocking.

It's just like LLC enabled or not. When you disable SVID then you force your voltage settings instead of internal auto voltage regulator so it works like idle is almost always as high as you set in BIOS, load depends on some factors and how the motherboard is managing CPU power. On ASRock in both cases I had similar voltages. On ASUS when SVID was disabled then I had higher idle than load voltage but when it was enabled then I had to set +0.05V higher CPU voltage to keep it stable. Hwinfo64 was showing ~1.288V load without SVID and ~1.35V load with SVID. In both cases it was minimum voltage at which my 9900K@5GHz passed 1h+ AIDA64. Difference in temps was about 10°C but it was already above 90°C and some cores were from time to time passing 100°C (custom water).

If you run memory at higher clock then manually adjust IO and SA. 1.3V is usually enough for 4000 memory clock. Also 1.2V IO should be enough. Once you enable XMP on higher frequency memory kits (or OC above some clock) then at auto it can be like 1.35-1.40V and 1.30-1.35V. All depends on the motherboard.

 

[MaddMutt]

I have to toss my results in here as I have done 2 i7-8700k and I broke the first one. I modded the 1st one to work in a z170 board. This could have been the reason that it broke I purchased a z370 board to go with my 2nd i7-8700k.

Here is my First i7-8700k @5.0 and Cache @5.0. My temps where ~70c - 75c @6c/12t. I used KPx as my TIM for the inside and outside. Cooling was a old H100i with 4 x Deltas
To go faster I had to drop to 6c/6t @1.35v. This got me to 5.3 and 5.1 with the same temps.

https://www.overclockers.com/forums...nox-AIDA64-Cache-and-Memory-Competition/page4

View attachment 203403

My Second i7-8700k @5.3 and Cache @5.0. My temps are again 70c - 75c but this time it's 6c/12t @1.45v. I used LM (CLU) for the inside and KPx for the outside. Cooling was a old H100i with 4 x Deltas The sun has come out so I will not be trying for 5.4GHz. Maybe tomorrow

View attachment 203405

View attachment 203406

 

[caddi daddi]

BOOOOOO,high temps, BOOOOO!!!!!!
it's in the mid 60's here today and I am waiting for more cold also.

 

[Alaric]

Mid 60s here after a week of 40s-50s and rain. I have the motivation to get some cooling, just not the cash. LOL

 

[Witchdoctor]

Why not ?

 

[Alaric]

I don't have enough chips to start killing them at random. LOL And one of the ones I really want to play with is borrowed, so I want to be nice to that one, especially.