How to have lower vcore on AVX loads (negative offset) than on other loads?

Joined
Jul 10, 2019
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I have an Asus Z270-A Mainboard and an i7 7700k.
I have quite a hot 7700k and so far I can maintain 4.8/4.9 at about vcore 1.27-1.29, but despite my NH-D15 cooler that has been reseated just recently, my temps get over 80 in non AVX scenarios.
For AVX loads I get over 95°C (for 1.28 vcore), despite having a multiplier of -2 for 4.9Ghz, which is because the vcore stays nearly the same as for non-AVX loads. At 4.7Ghz, AVX (etc.) instructions in Prime96 and Intel Burn Test run fine at vcore of at least 1.23-1.25, but all other loads require more.

So, how can change the Asus BIOS settings, so that I have vcore for AVX loads at most 1.250v and for all others, say 1.280v?
I haven't seen any guide do this and I am at a complete loss as every setting I have tried (adaptive mode with offset, offset alone, manual with LLC settings), I mostly get the opposite, AVX loads get slightly higher vcore whereas with Cinebench r15 load I get lower ones so that it crashes.

I think having separate vcore settings are quite worthwhile when one has upper thermal limits that must not be overstepped, or is this procedure just dumb?
Any ideas on how to do this with Asus MBs?

So my problem is not AVX is not stable ( therefore the minus offset to make it stable) but the vcore with avx stable and temps acceptable is too low for non_avx loads that run at 4.9Ghz. Other overclockers mostly do the other route, upping vcore for AVX but having lower vcore for non AVX, which is not possible for me with my temps, and my route seems to suffice better for the system imo.

Is there a way in terms of power throttling to get the result I want? For AVX, I have package power of 115w (IA core - 112w), and non AVX about 95w (IA core - 92w). So I would set PL1 to about 105w and PL2 to 95w? What happens then with vcore when AVX gets throttled to 95w?

Would it also make sense to have a LLC with more vdroop (as for AVX it requires more power?) or will AVX loads have the same vdroop as other instruction sets?

At the moment, I found that adaptive mode (overwrite 1.265 - Auto) gets me 1.264v max which is stable for both 4.7Ghz avx (due to LLC, I sometimes get 1.248 with AVX which is good!) and 4.9Ghz non-avx load.Let's see how the power throttling handles both. Interestingly, For Intel Burn Test (uses also AVX), vcore stays at 1.264v, but in prime95 it will go down to 1.248v.
 
Joined
Jul 10, 2019
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Any suggestions? I also got my "new" 8700k back today and I found out that it runs stable up until 4.9Ghz@1.296 and for AVX load with 4.7Ghz@1.264v vcore. 5Ghz is not really a viable option with that specific CPU, but at least the vcore seems a bit better I guess.

To get these values via Asus BIOS,I have set SVID behavior : best-case scenario, and for adapive mode I chose overwrite 1.330 - Auto, LLC is level 5, as with 6 I won't get the AVX load vdroop as wanted and described in the first post.

In Prime95, AVX loads will cause the vcore to drop to 1.248 which will get errors after 20 min or so in one worker, so far I could not find settings to get it to 1.264v as in other programs like ffmpeg or IntelTestBurn (I think it uses AVX2). So I nearly succeeded with my returned 8700k, only that I lack the 16mvolt for prime95 in AVX load to get prime stable.
Manual static vcore will cause too high temps for AVX load sadly as I will need at least 1.280 to get 4.9Ghz working in non AVX load cases.

Changing other BIOS settings like SVID behavior, haven't gotten me the needed adjustment yet as either 4.9 load gets to high vcore and excessive temps or too low vcore so that I freeze up. I would be great if one could adjust seperate voltages for the load type and not fool around with SVID table options. Is there a way to change the SVID values manually, like for AVX load scenarios?
 
Joined
Jul 10, 2019
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Update:
After flashing the ROG MAXIMUS X HERO BIOS to Version 2102, the SVID Tables and Adaptive Mode in general has changed its behaviour to AVX/FMA3 loads.
Now the vcore will actually increase in these load types and nothing so far could reverse it. I also returned my 8700k as it was showing HW-Errors in prime95 while using FMA3 loads at 4.7GHZ with few cores.

So I will be upgrading to 9700k soon and I will probably settle for a mild OC then as it already turbos to 4.9Ghz. A 9900k would be overkill with air-cooler though. I just hope that I won't get a lemon at already stock frequencies anymore.
I also found out that OCing the memory controller is really pushing the overall core temps way higher than expected. so there is an additional avenue for optimization I guess.
Is it expected that the 8700k will fail at FMA3 loads with all cores at 4.7Ghz with voltages in the range of 1.296-1.344? I think over 90% of them should manage this, right?
 
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