Boost Clock? 2.7Ghz?

[bear95]

I tested the CPU performance with Prime95 on Radxa x4.
However, the clock only reached up to 2.7Ghz.
And, it operates at an average of 2.2Ghz during the test.
The temperature did not exceed 70 degrees, so it does not seem to be throttling.

The product spec is 3.4Ghz as the maximum.
Why is this difference occurring?

[incognito]

You need to enable C states in uefi. It should be the default though.
3.4 GHz is a single core turbo speed, the max for 4 cores it 2.9, if I recall correctly.

[ryann]

You need check TDP PL1 and enable C-state
These two items will affect the CPU frequency

[SinisterPisces]

You need check TDP PL1 and enable C-state

Are there instructions for undrestanding how to adjust PL1?

EDIT: Found them here:

Frequency Locked at 2.90

Hi, ive installed my own cooling solution, and i haven’t been able to get past the 2.90 ghz frequency, it appears to be under clocked. You guys advertised a boost clock to 3.5, is there maybe a beta bios that i could flash that gives me more control? Am i missing anything? Secure boot would also be a great feature! So far its been a fantastic product!! my email is honeybaj@protonmail.com

Set PL1 over 12000, with C-states enabled.
Thanks, @ryann .

[SinisterPisces]

After enabling c-states and setting PL1 over 12000 (12500 on my setup), I did see 2.9 GHz all-core when I stressed it, and 3.0+ GHz single core, but pretty quickly during the stress test, those numbers went away and it ceilings at 2.2 GHz again.

PL1 Time Limit is still at 0 (the default).

[ryann]

What is your CPU temperature during stress testing? Make sure you are not hitting the power consumption wall or temperature wall causing throttling

[SinisterPisces]

Thanks for your message. Here’s the output of stress after 17 minutes. I’m stable at 44 C across all cores, and it pretty much sits at 2.4 GHz on all cores.

BIOS v004;
C-states are enabled;
PL1 enabled and set to 12500 (“over 12000,” per your previous message);
PL1 Time is default “0;”.

Proxmox (Debian) reports the CPU is in performance power mode on all cores.

I’m really happy with this as-is, but if I could get it to 2.9 GHz all-core, that’d be awesome.

[incognito]

Try increasing PL1 to 15 - 17.5 W

[SinisterPisces]

Thanks! I’ll give that a try.

But I have to admit, I’m pretty confused about the math behind PL1 at this point.

12500 (12.5w?) translates to a measured 6w package power in stress/s-tui.

Is the measured package power under load just half of PL1? 17500 would push it to 8.75w?

[incognito]

No, PL1 should translate to what it says. The package power it probably not reported correctly by s-tui.

[SinisterPisces]

I hadn’t considered that s-tui might be incorrect. It recognizes the N100 and might just have the “max power” hard coded to 6w.

Are you aware of a tool that reports N100 power draw correctly in Linux? Powertop?

Do we know the max PL1 value the BIOS recognizes as a legitimate setting? I’m going to attempt 17500, but I’m curious how high we can actually go. I think ETA Prime went up to 20w on his.

[incognito]

6W is just the TDP of N100, which is the power it uses at the base speed (800 MHz).

You can also try to edit the PL1 override if there are turbo settings. I never knew what these did because they seem redundant.
But I don’t know about a good tool under Linux. HWinfo is nice but it works on windows only…

[SinisterPisces]

Just experimented some more. Didn’t really get anywhere, unfortunately.

1. Setting PL1 to 17500 behaves the same as 12500: Boost to 2.9 GHz for 25 seconds, drop to 2.3.
2. Setting the PL1 Timer to 128 has no effect: it’s still 25 seconds.
3. Enabling the PL4 override (the boost forever until you overheat) override has no effect.

According to s-tui, total power draw never exceeds 10w, though it’s divided up between the package, core, and psys in varying amounts that I can see change while it’s doing things. Package maxes out at 6 watts and core fluctuates between 4.7-4.9. Psys sits at 0.2.

It’s almost like it’s ignoring the power level settings entirely. They should have SOME measurable effect.

1. This makes me think there’s some other setting in BIOS V004 that causes it to ignore these settings.
2. At minimum, setting the PL1 timer to 128 should have allowed it to sustain a 2+ minute all core 2.9 GHz boost, which makes me think the settings are being ignored.

@ryann, is there anything else in the BIOS that might need to be adjusted? I’m really confused at this point.

Also, does it matter if I’m using the PoE+ hat? The hat can do 25w, so that shouldn’t make a difference, right?

[ryann]

It looks like the PL1 setting not work, you need set PL1 here:
Advanced–Power and Performance–CPU–View/Configure Turbo option–PL1 override (enable), PL1 to 12500 or higher, then press F4 save and exit
And did you see the Power more than 6w in S-tui when just start the stress

[SinisterPisces]

@ryann Sorry; I replied before seeing your message above.

I never saw total power exceed 10 watts during the stress test.

Advanced–Power and Performance–CPU–View/Configure Turbo option–PL1 override (enable), PL1 to 12500 or higher, then press F4 save and exit

I didn’t even realize there was a second group of PL settings hidden away there. I’ll try this.
… And it works.

@ryann Do we also need to disable the PL1 settings in the main part of the BIOS? Or does it just ignore those either way?

[ryann]

I think just ignore it will be fine

[SinisterPisces]

I held a 2.9 boost on all cores for 30 minutes. I think it’s working.

Thanks again for your help.

[incognito]

These are the settings I mentioned in my previous post.

Can someone explain why there are 2 sets of these settings on N100 CPUs and which one has an effect in which situations?