Frequency Limit Global for Ryzen 7 7840HS (Zen 4 / Phoenix CPU)

[birdie]

HWiNFO64 says Frequency Limit Global for my Ryzen 7 7840HS CPU is 4500MHz which is far below what AMD says it should be boosting at which is 5.1GHz.

Could this limit come from the BIOS? I'm looking at HWiNFO64 output and I don't see any limits (power, voltage, amperage, etc). being hit.

The CPU never ever goes above 4.5GHz no matter the load. The CPU is pretty much sitting idly.

 

[Martin]

This is a dynamic run-time limit that aggregates several run-time parameters like TDC, EDC, PPT, Thermal, and some other internal ones and decides what's the actual maximum clock allowed.
So it's not a fixed limit defined by BIOS, but constantly evaluated by the CPU/SMU.

 

[birdie]

This is a dynamic run-time limit that aggregates several run-time parameters like TDC, EDC, PPT, Thermal, and some other internal ones and decides what's the actual maximum clock allowed.
So it's not a fixed limit defined by BIOS, but constantly evaluated by the CPU/SMU.

But Martin, as you can see on the screenshot, no parameters' limits are even close to their maximum There's no throttling either. Temperatures are very low.

Is is possible to hard limit the CPU maximum frequency in BIOS/UEFI?

Is it possible to write to some CPU registers to unlock it? Though considering it's a PRO SKU I guess it's all tightly controlled.

 

[Martin]

Yes, I saw that and I'm wondering too. There are also some other internal parameters involved in the decision making which are not visible to the public and I'm not allowed to talk more about that.
Perhaps one of those parameters is enforcing this limit.

 

[birdie]

Yes, I saw that and I'm wondering too. There are also some other internal parameters involved in the decision making which are not visible to the public and I'm not allowed to talk more about that.
Perhaps one of those parameters is enforcing this limit.

I'm reading it as "Limits are enforced/imposed by BIOS". Hopefully they will release an updated BIOS with a lifted restriction. Why did HP do it to me?

Thanks a lot anyways!

BTW, there's something which looks like an error in reporting:

Core Powers Maximum is reported as 109W. I don't think this is possible for this SKU.

And L3 cache running at 287GHz is quite unusual. I don't think silicon can run at such a speed. It's not physically possible

 

[Martin]

Yes, I noticed that too. Must be some issue in the SMU as HWiNFO shows what the SMU reports.

 

[birdie]

Yes, I noticed that too. Must be some issue in the SMU as HWiNFO shows what the SMU reports.

I'm not sure what you're hinting at. A HW failure? AMD Phoenix APU peculiarity?

I've used the laptop for just three days. Please do not frighten me

 

[Martin]

No, a SMU software/firmware failure in reporting of those parameters. Might be fixed with a new BIOS update.

 

[crs_tzep]

Same problem here, buyed a new lenovo laptop with 7840Hs, installed win11 + drivers +programs, used the computer for half of day, on various profiles, played AOE 2 DE, run cinebench, web pages...

Max frecvency was 4.9 GHz. If i can fix it today I will request a refound!

 

[Zach]

The 7840HS is AMD configurable 35-54W TDP CPU.

https://www.amd.com/en/products/apu/amd-ryzen-7-7840hs

I suppose that it needs all 54W for the 5.1Ghz clock limit (?)

I also believe that each laptop vendor can limit max frequency as "wishes", within that 35-54 range, maybe depending on the cooling solution or the PSU or whatever else...

Same problem here, buyed a new lenovo laptop with 7840Hs, installed win11 + drivers +programs, used the computer for half of day, on various profiles, played AOE 2 DE, run cinebench, web pages...

Max frecvency was 4.9 GHz. If i can fix it today I will request a refound!

What is the max CPU PPT (W) you see on HWiNFO?

 

[crs_tzep]

Hello again, Today I changed the computer with a similar one.

The second one has the same problem, this one being stuck at 4.96GHz
The CPU is ok in stress tests (as expected) however never reaches peak frequency (pictures).

There are no settings in bios and I use the performance mode.
I'm starting to think is a BIOS problem/bug!!!


opinions?

 

[Zach]

Hello again, Today I changed the computer with a similar one.

The second one has the same problem, this one being stuck at 4.96GHz
The CPU is ok in stress tests (as expected) however never reaches peak frequency (pictures).

There are no settings in bios and I use the performance mode.
I'm starting to think is a BIOS problem/bug!!!


opinions?

Your Frequency Limit - Global is 5.1GHz though.
But look at that EDC Limit (CPU package current)... its 120%
Maybe that is holding the CPU from hitting really the 5.1GHz.
Something is not right
Also the current (=live) value of EDC is high (97.8A) which alone indicates some serious workload, but everything else (CPU/Core usage, effective clocks, temperature) suggests the exact opposite.

 

[crs_tzep]

At this point I think I'm going to trobleshoot for the weeeknd and then 95% return the laptop and move to an other product/brand with a differnet cpu

I will try a linux... however it makes me sick at this point!

 

[Zach]

At this point I think I'm going to trobleshoot for the weeeknd and then 95% return the laptop and move to an other product/brand with a differnet cpu

I will try a linux... however it makes me sick at this point!

Did you ever contacted vendor customer support?
I think you should do that before anything. At least if they can give you info about it, or the CPU specific limits on this particular laptop.
Are there any documents that came with it that may say such info?

The aspect that I didnt think of earlier is the iGPU. Having a powerful iGPU into the CPU can utilize a large portion of the overall package power.
It all comes down into what power budget has the vendor configured for the entire CPU/iGPU.
This laptor has any dGPU on or graphics are power only by iGPU? Maybe the 7840HS is meant to hit that 5.1GHz only when dGPU is present while the iGPU is low power mode or even off

Im not saying this is the case... only trying to think about all aspects.

 

[crs_tzep]

First: thank you Zach for all the time you waist with me.

Second: I have spoken with Lenovo (first attached image, and she said something similar with what you are telling me) and posted on their FORUM with no response, nothing came with the laptop in the box.
This laptop comes with IGPU (780M) only, your observation about the low power could be the case (second image + PDF) but I don't think so, why would they state 5.1GHz and then not deliver it !?

I would be curious if anyone witch uses this CPU can test on a different computer !?

I have posted including to the AMD community and I have no clear answer yet.

 

[crs_tzep]

And remember I returned 1 laptop, the other was capped at 4.909Ghz this 1 is capped at 4.966GHz, I should order 10 laptops and select the one with the higest CPU frecvency (I'm jocking). If I return this one I'm done with Lenovo.

This laptop is a best buy where I live, metal construction , strong cpu+igp, good screen and portabillity + the most important it has only 1.3Kg!

The closest thing I can afford is an entry gaming laptop witch ar bulky and heavy! This is why I'm trying to solve this.




EDIT: I guy from the forum replied with a screenshot form his computer (same config 16", mine is 14") I see his voltages are bigger then mine?! WHY?

 

[Zach]

EDIT: I guy from the forum replied with a screenshot form his computer (same config 16", mine is 14") I see his voltages are bigger then mine?! WHY?

This guy done anything to it?

It also runs higher wattage (60W PPT) and +20~25C higher than yours. I bet its louder too.
+0.05V for +150MHz and a lot hotter, I dont think its worth it.
It may have the same components but as a 16" it may have also slightly bigger cooling solution, though the temperature (95C) does not saying that.
We are talking about an occasional +3% more boost and that in pure performance may by like +1%, if any...

Unless the laptop has a beefier/louder cooler that makes the whole device heavier as well, its tough to squeeze every last watt from a CPU installed on a lightweighted one and keep temp controlled.
Now that I learned more about it, I find it reasonable. And like I said you're not loosing a ton of performance. It would be unnoticed and within a margin of error.

 

[crs_tzep]

He did nothing it's stock , He said he benchmarked it before to trigger the turbo boost...
this is mine after benchmark, so not the much difference in term of heat, my power is bigger ... I really don't know I feel unsettled with this ....