C-State/power saving issues with per core overclocking + Intel Thermal Velocity Boost + iCUE

[Astral85]

 

Dear CUE 4 software team,

 

There is a high level issue with CUE 4 in which CUE 4 prevents the CPU from entering low power C-States/Speedshift when Core ratio: per core overclocking is used. I am using an Asus motherboard but I believe per core overclocking is common on other branded motherboards as well. Similarly CUE 4 will prevent the CPU entering low power states when Intel's Thermal Velocity Boost feature is enabled. Please see attached screenshots of where these options reside in the Asus BIOS as well as a HWiNFO screenshot from my system demonstrating the issue in which the core clocks are kept at maximum frequency with CUE 4 running when the system is idle. 

 

If this can be looked into it would be much appreciated. 

 

 

 

 

 

 

Edited August 7, 2021 by Astral85

[LeDoyen]

you have an average CPU usage that's quite high for "idle".

what's taking so much? that will prevent the CPU from going to lower C states. Obviously, iCUE is a bit of a power hog, but if you can limit processes running in the background it should quiet down.

And watch your VCCSA, VCCIO and Dram voltages, they are like borderline dangerously high. Vcore isn't stellar either.

For VCCSA and VCCIO you should be able in an asus bios to set voltage caps to avoid having automatic voltages runaway like that.

[c-attack]

There is something unique in the way CUE reacts specifically to the per core clock setting in the BIOS.  This applies to the default Intel specifications and behavior as well, which has individual core clock settings.  So if you set it to "per clock" and "5.1 x 8 cores" (or any other staggered set of clock speeds) it reacts aggressively.  If you set it to "All core" and 5.1 (8 cores again), it steps down at idle and uses about half the wattage.  Since the per core clocking is how most recent CPUs are meant to be used, it does create something of a problem.

Edited August 8, 2021 by c-attack

[Astral85]

3 hours ago, LeDoyen said:

you have an average CPU usage that's quite high for "idle".

what's taking so much? that will prevent the CPU from going to lower C states. Obviously, iCUE is a bit of a power hog, but if you can limit processes running in the background it should quiet down.

And watch your VCCSA, VCCIO and Dram voltages, they are like borderline dangerously high. Vcore isn't stellar either.

For VCCSA and VCCIO you should be able in an asus bios to set voltage caps to avoid having automatic voltages runaway like that.

Asus set auto value VCCSA/VCCIO relevant to what memory frequency and timings you have dialed in. As I'm overclocking quad channel memory I think the voltages are relevant and offer the most stability. I don't think Asus provide these voltages if they're unsafe.

I believe the high thread usage is mostly related to CUE. I've attached a screenshot of what my task manager typically looks like. Closing the CUE software off will instantly let the CPU enter relax into Speedshift and C-States so the usage and clock frequency is not related to any other program/background process.

1.4V is very normal when using Thermal Velocity Boost to boost the CPU to 5.3Ghz or beyond in light load desktop loads. Under heavy load the core ratio will drop according to temperature limits set with TVB. In my case I let it drop to 5.1Ghz all core at around 1.3V. These voltages can be offset further with the V/F curve.

Edited August 7, 2021 by Astral85

[Astral85]

The issue doesn't seem to be CPU usage but something to do with the per core functionality as c-attack mentions. If you instead set core ratio to sync all cores the CPU happily enters low power C-states and Speedshift with CUE 4 running. 

[LeDoyen]

seems like it yes.

I guess setting a per-core with the same frequency across the board kind of makes it an all core overclock, but with weird behaviour as you experienced.

 

For the voltages, i mostly run my 10900k stock with an occasional 5 or 5.1 overclock. but even at stock the VCCIO and VCCSA reach 1.35 - 1.37v.

If i set it manually in the bios, you remember the color of the number varies if you start to go high (appearing yellow) or to unsafe levels (purple).

VCCSA turns yelow at 1.2V and purple at 1.3 😛 the bios will push ridiculous voltages on auto sometimes. stock values are around 1 volt.

I capped it to 1.2V max, because auto just goes way too high even when there's no need for more voltage. the PC boots just fine at 1.1v too.

Same story for DRAM voltage. mine set it to 1.41v for 3600 CL16 which is horrendous. had to set it manually to 1.34v.

your 3866 CL19 is actually higher latency than that, so i don't know. if it's a manual OC, then it may be worth testing what gains you have when going for low latency vs high frequency. sometimes you lose performance trying to reach high frequency but losening timings to get there ^^

for Vcore, forget what i said, i think i had the average frequency in mind from your screen capture, which was ~5.2 ^^' your Vcore makes sense for 5.3.

 

Edited August 8, 2021 by LeDoyen

[Astral85]

Maybe Asus changed this with Z590. On Z590 it seems to predict VCCSA/IO rather than give you the max levels at the outset. I was already using VCCIO 1.3V and VCCSA 1.35V manually but running into errors with my RAM overclocks. The errors went away when I took Asus auto values for IO/SA. However I also suspect CPU Vcore is linked to RAM OC stability and may have not have had truly stable Vcore. I think I have Vcore sorted now and could try lowering IO/SA. I'm pushing a quad channel 3466 kit to 3866 CL 16. Quad channel is going to put more strain on the CPU IMC, Vcore IO and SA voltages. It all needs to be stable... 

 

So did you try per core yourself?

 

Edited August 8, 2021 by Astral85

[LeDoyen]

I do, but i don't push as hard. i keep 5.3 on two cores, then step down to 5, 5.1 or 5.2 depending on temperature. the gains in game are so minimal that i only overclock for points on 3Dmark. 3 or 4 fps are not worth doubling the CPU power draw in my eyes. On the daily, i use stock settings with only a tweak to TVB to account for unlocking the power limits. 

I locked whatever parameters i need in bios (like those IO and SA voltages) and run the OCs with intel XTU profiles i made. can't be bothered to reboot 🙂

I guess the bios gives you values that are guaranteed to work on the worst silicon they tested, to make sure it posts. Otherwise i cant explain why it pushed my VCCSA so high on stock settings.