How to achieve maximum turbo frequency

[noob25002]

Hello,

Setup:
System board: ASUS TUF B360-Plus Gaming
Ram: 2x 8Gb 2133mhz DDR4
Gammaxx 300 CPU Coller
Latest Bios.
Win 10 x64.

According to Intel's specifications, the turbo table of this cpu should be the following:
4,000 MHz (1 core),
3,900 MHz (2 cores),
3,900 MHz (3 cores),
3,900 MHz (4 cores),
3,800 MHz (5 cores),
3,800 MHz (6 cores)

No core has ever gone over 3.8ghz. I stress tested 1 core individually, 4, then 6.
The board does not have MCE or XMP.
Tried setting the multiplier to 40 for the first core, the rest are auto.
Tried all the bios settings, maxed out everything.
In the bios it states the target for turbo is 4000mhz, and 3700mhz for cache.

What settings do I need?
Am I being limited by the board?

 

[LTC8K6]

What CPU is it? 8400?

 

[noob25002]

Yes, it's a i5 8400.

 

[LTC8K6]

Do you not have 2666 ram for it?

Maybe leave the BIOS at defaults?

Try the CPU-Z benchmark.

Sometimes it's hard to get just a single core to load up.

You can run the Intel XTU . You can look at many parameters of the CPU and see what's going on with it.

 

[noob25002]

I only have the 2133 ram.
Tried all the bios settings, default included.
Tried the CPU Z benchmark, no difference.
The multiplier does not want to go over x38.

In XTU:
The cores seem to have the right multipliers.

https://imgur.com/a/iddh6tV

This platform does not support overclocking
Max core frequency 3.78ghz.
Procesor cache frequency 3.49ghz.

Power limit throteling- No.
Range - No - Yes.

Thermal throteling- - same as power limit.
Current limit throteling- - same as power limit.
System board VR - - same as power limit.

LE: in the comparisons page on the website , besides the others having z370 boards, the Turbo Boost Power Max was increased.
Should I attempt to raise it as well?

 

[LTC8K6]

Strange. What do you get if you set everything to default, leave all of the cores active, and run a single thread bench, like CPU-Z? I'm not clear on whether you tried that, or you are disabling 5 cores for the single thread test.

 

[noob25002]

That's what I did from the beginning, ran stress test on one core, stayed at x38 multiplier.

Disabled 5 cores from BIOS, here's what I got:
1x sits at 4000mhz, x40 multiplier.
Uncore is at 3700, x37 multiplier.

Disabled 4 cores in BIOS:
2x cores - 3900mhz, x39 multiplier.
Uncore is 3600mhz, x36 multiplier.
Tried setting the multiplier x40 for the 1st core, the 2nd left to auto, ran stress test on one core. No change.
4x cores, same as 2.

Intel speed step is disabled.
Intel speed shift is enabled.
ACPI timer is at 3580mhz.
Virtualization is enabled.
Cpu power enhancement is on. Is this the Multi core enhancement?

On 6 cores the Uncore sits at 3500mhz/x35 multiplier. Is this the problem?

 

[LTC8K6]

Maybe try actually clearing the BIOS with the jumper on the board, make no changes, and see how it acts after that?

Make sure Windows power plan is set to balanced or high?

I can't seem to learn anything about "CPU power enhancement".

 

[noob25002]

Windows is in High Performance.
Using CPU ID, HWINFO 64.
I don't think this makes a difference, the cpu is a tray, not a boxed one.

Cleared the BIOS, made some tests, and changed some things.
I think I found the issue: C states.
No difference between Auto and Enabled.
Enabled it has C8 and C9 disabled, but enabling these 2 makes no difference.

Was also using CPU Burner, which seems to spread out the task even if 1 thread is tested.
Tested with the CPU Z bench/stress cpu.
The behavior of the 3 types of bench/stress methods is erratic.
17.01.64
Benchmark and stress are contained to 1/2/etc cores.
The other 2 spread the workload around: 19.01.64 (beta) and 19.01.64 AVX2 (beta).
The 17.01.64 keeps the cores at x38 during stress, but keeps them at x39 during benchmark.
And this behavior can change, meaning it can keep the cores x39 during stress and x38 during benchmark. In some test the cores will be fixed at x38, and when performed again , they will go to x39.

The multiplier still does not go to x40 and x37 for the cache, but it does go to x39 and x36 for the cache, in many instances for all 6 cores.

Maxing out the settings in AI suite 3 did not make any difference.
CPU power enhancement does not seem to have any effect (2 settings Auto/Disabled).
Intel SpeedStep and SpeedShift have no effect.
Tried setting in BIOS from Auto to Performance. This maxed out some settings, but disabled C states.
Tried setting 1 core at x40, then all 6 cores at x40 from BIOS.

What else could I do to get the 1 core to 4ghz?
Is this application related? Do I need some other benchmarking/stress utility?

 

[LTC8K6]

I'm not sure where to go now.

I haven't seen this before. I've never had an Intel chip not go to it's single core turbo with a single thread load.

 

[noob25002]

What could possibly be wrong with my setup then?

Tested Prime 95 with 1 or 2 threads. stays at x38 and spreads the task to all 6 cores.
CPUID powerMAX AVX/SSE tests all 6 cores, actually downclocked them at x33 towards the end.
OCCT was containted to 1 core, but did not exceed x39.

What other software could I try, or at this point, it does not matter?

LE:tested Prime 95 with affity just for CPU 0, did not pass x39.
Same with CPU Burner.
CPU Z and powerMAX resets it's core affinity.

The way Turbo Boost work as far as I understand, is that if a core were to go at 4ghz, the others would reduce frequency, and they are not.

 

[RLGL]

Funny, I just saw a very similar post in the Asrock board forum tonight. The bad news Asrock support connected with the poster to tell him how to work this out. He did not provide details. Evidently this is a common issue. Link to post

 

[noob25002]

iGPU is disabled.
Can't find the ring-core multiplier offset.
Can't find the BCLK overclock feature, although in BIOS it says it's 100mhz.

I didn't mention this before, but the bus has never been 100mhz. It stays between 99.7 and 99.8mhz.
As a result the cpu speeds have been 3790 or 3890mhz. I didn't think much of it until I saw the screenshots in the other thread. Those vary a bit as well, but on my setup it has never been 2800/3800/3900 exactly.

Went into bios and set the first core multiplier at x40, and x28 for the rest.
In windows all the cores stayed at x28 regardless if a benchmark was running or not.

I've registered on an asus forum, but I have to be approved.

 

[noob25002]

Did not get any response on the asus forum.
Have sent a ticket to asus.

 

[noob25002]

I managed to get it to x40 on a single core in idle and load.
1st picture idle, you can see cores clock and cores ratio go to x40/~3920MHz. Uncore goes to x37/~3690MHz.
2nd picture Core 0 is at 100%.

https://imgur.com/a/p3sbQ5h

In idle all the cores go to x40 very easily, in load the one core achieves x40 sporadically.
Some software will prevent the cores to go to x40 in idle or load, even if they are open and do nothing: Intel XTU, SpyHunter 5.

It needs to be on full load on one core and idle on the rest:
OCCT can assign itself to one core (with one thread).
Prime 95 (cpu stress) needs to be assigned to one core via Task Manager. Needs one or two threads, six will crash it.
CPU Burner will not get the core to x40 regardless of the settings above, with one or more threads.
CPU Z only has one benchmark that gets one core to 100% (Version 17.01.64), but it uses the other cores as well. It resets the assigned cores via Task Manager.

When it goes to x40 the other cores do not go down in frequency as Intel's documentation on this technology claims.
I thought that it was a headroom issue, so I tried power saving and balanced power settings, and while the core frequency did go down in idle, in load the other cores would still go to 3.8/3.9GHz. The one core would still reach 4Ghz with these 2 power settings as well.

I noticed In Intel XTU while 5 cores were disabled in BIOS the Turbo Boost Power Max and Turbo Boost Short Power Max were set to Unlimited. I set them to Unlimited after I enabled all cores, but made no difference. This setting would resets itself after a reboot.

Support told me this is normal CPU behavior, set by Intel.

Also, can monitoring software display Max Core Frequency per core?