i7 8086k drops to 4.7ghz on a test when its over clocked to 5.2ghz

[renomad172]

i7 8086k drops to 4.7ghz on a test when its over clocked to 5.2ghz

any idea why that's happening?? when your idling away it sits at 5200mhz but putany tests multicore tests on it, it flat lines back to 4700mhz, single core tests it stays at 5200mhz

it never used to do that it used to stay flat out on its over clock (which once was 5400mhz the day I got it!! but since a bios update and I had to do a CMOS reset I can't get that back stable!)
 

but main issue now is the issue above! i want my full 5200mhz

running 

asrock z370m pro4 board
i7 8086k cpu (liquid metal)
full home made water cooling (front 280mm rad, rear 140mm rad, cpu block and memory block - in a tiny themaltake h17) temps are around 50 degree c under cinebench tests etc
gskill trident z 4266mhz kit (running at 4133) 
wd black 500gb m.2
rtx 3060 12gb 

thanks for any ideas or help!!


 

[Dedayog]

Are you 5.2GHz on all cores in your OC? or just 1 or 2?  

[Guest]

Set the avx multi to 52.

[renomad172]

that's how its set atm, would it be "minimum cache ratio" set that too 52? where the 4300mhz comes from too i dont even know

[Guest]

Where it says AVX ratio second screen shot is set to auto. That will default 4.7ghz all core load.

 

Cache is separate from cpu core overclock, don't touch that yet.

[renomad172]

7 minutes ago, ShrimpBrime said:

Where it says AVX ratio second screen shot is set to auto. That will default 4.7ghz all core load.

 

Cache is separate from cpu core overclock, don't touch that yet.

Ah fair just put 52 into that then is it?

[renomad172]

You can only put 31 maximum into there anyway and it says lower number is better so I tried 3 and same deal on cinebench straight to 4.7 then down to 4.35 on second part of test (using R23)

[unclewebb]

You might have to specifically set your long and short turbo power limits. Not sure what the Auto setting means. 

 

Run HWiNFO64. It will show you a list of throttling reasons. Power limit throttling is common.

 

AVX Ratio Offset should be set to 0.

 

I set both turbo power limits sky high so they never interfere with maximum performance.

 

[renomad172]

13 minutes ago, unclewebb said:

You might have to specifically set your long and short turbo power limits. Not sure what the Auto setting means. 

 

Run HWiNFO64. It will show you a list of throttling reasons. Power limit throttling is common.

 

AVX Ratio Offset should be set to 0.

 

I set both turbo power limits sky high so they never interfere with maximum performance.

 

Yer im sure i did them before one was 120 one was 150.. guess short is the highest.. and maybe i had the AVX at 3 or something it's been so long since I touched it like this it's like im a n00b again

[unclewebb]

@renomad172 120 Watts will result in severe power limit throttling during a long benchmark like R23 and an AVX offset of 3 will lower your CPU speed 300 MHz. For full speed, fix those two issues. 

[renomad172]

If you put 0 for anything or leave it blank and move on it defaults to AUTO

 

and I don't know about the power limits I'm just going off old pics when it worked ages ago

[unclewebb]

Set the Long and Short Duration Power Limits to 4095 like I suggested. This is the maximum possible value. That is what you want to avoid power limit throttling. Many Asus boards use this value when overclocking. 

[renomad172]

4 hours ago, unclewebb said:

Set the Long and Short Duration Power Limits to 4095 like I suggested. This is the maximum possible value. That is what you want to avoid power limit throttling. Many Asus boards use this value when overclocking. 

its asrock wont that matter?

[Guest]

4 hours ago, unclewebb said:

Set the Long and Short Duration Power Limits to 4095 like I suggested. This is the maximum possible value. That is what you want to avoid power limit throttling. Many Asus boards use this value when overclocking. 

It didn't dawn on me that board would power restrict like that. I'm spoiled with my Hero. But just wanted to be sure to thanks for all the help. So thank you. 

[-rascal-]

9 hours ago, renomad172 said:

that's how its set atm, would it be "minimum cache ratio" set that too 52? where the 4300mhz comes from too i dont even know

 

AVX Offset only applies when an AVX workload is detected.

It will drop the CPU frequency by the set offset.

If your CPU is x52 (5.2GHz), setting the offset to 3 would mean during AVX workload, the CPU multiplier gets dropped to x49 (4.9 GHz).

If you set the AVX Offset to 0, then CPU will run at full 5.2GHz.

 

CPU Cache Ratio =/= CPU CPU Ratio.

If you are going to mess around with the cache, it should be 3x or 4x less than CPU Ratio.

Running it 1:1 typically causes issues.

 

I would also run the stress test again, but this time, have something like HWiNFO open.

Check if the CPU or VRMs on the motherboard is potentially thermal throttling.

The VRM and VRM cooling on that AsRock board is pretty tiny...IMO.

(I'm running a i7-8086K on an all-core OC of 5.1 GHz right now)

 

You can also put your Long/Short Term Power and Current Limits to max -- pull it off of Auto.

Whatever that may be.... 999 or 255, etc.

 

The 4300 MHz is your Cache frequency by the way...

Target CPU / Cache / BCLK Speed -- 5200 MHz / 4300 MHz / 100 MHz

• Target CPU = 5200 MHz
• Cache = 4300 MHz
• BCLK Speed = 100 MHz

[Guest]

5 minutes ago, -rascal- said:

 

AVX Offset only applies when an AVX workload is detected.

 

CBR23 - used for testing, it drops to 4.7ghz. 

Right AVX 0. 

You da man too.

[renomad172]

2 minutes ago, -rascal- said:

 

AVX Offset only applies when an AVX workload is detected.

It will drop the CPU frequency by the set offset.

If your CPU is x52 (5.2GHz), setting the offset to 3 would mean during AVX workload, the CPU multiplier gets dropped to x49 (4.9 GHz).

If you set the AVX Offset to 0, then CPU will run at full 5.2GHz.

 

CPU Cache Ratio =/= CPU CPU Ratio.

If you are going to mess around with the cache, it should be 3x or 4x less than CPU Cache Ratio.

Running it 1:1 typically causes issues.

 

I would also run the stress test again, but this time, have something like HWiNFO open.

Check if the CPU or VRMs on the motherboard is potentially thermal throttling.

The VRM and VRM cooling on that AsRock board is pretty tiny...IMO.

(I'm running a i7-8086K on an all-core OC of 5.1 GHz right now)

 

You can also put your Long/Short Term Power and Current Limits to max -- pull it off of Auto.

Whatever that may be.... 999 or 255, etc.

thanks for the in depth brake down mate, the cpu is defo no where near a thermal throttle i got real temp gt going when i stress it and doesn't go near 70 degrees like sometimes when gaming and other things 

the VRMs a possibility i will defo look at them 

the other thing is the lowest AVX offset i can go is 1 as 0 makes it to auto.. so stuck on that one what to do

ill see what i can do on the power as well tomorrow as its late now!! and waiting for my ryzen itx stuff to arrive so probs be back with other issues as well

[unclewebb]

2 hours ago, renomad172 said:

its asrock wont that matter?

It is an Intel CPU. The power limits are set within the CPU. They need to be checked when you have any full load throttling issues. HWiNFO reports the reasons for throttling. No need to guess what the problem is when it can tell you the reason. 

 

Set AVX Offset to Auto and it will set the offset to 0. That is the typical default. Prime95 has options to test AVX loads or non AVX loads. Once you fix your power limits, you should see the same MHz in either test.