N4200 Burst Frequenty (Apollo Lake)

Issues related to hardware problems
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TomvB

N4200 Burst Frequenty (Apollo Lake)

Post by TomvB » 2018/02/15 05:41:25

Hi All,

I'm currently testing CentOS 7 with the Voyo vmac mini (v1) N4200 / bios unlock update.

The N4200 CPU can burst up to 2.5ghz, but CentOS only shows 1.10Ghz, the base frequency.
See: https://ark.intel.com/products/95592/In ... to-2_5-GHz

Windows 10 is showing up to 2.5Ghz when I burst the cpu.
cat /proc/cpuinfo is showing max @ 1.10ghz

1.10Ghz or 2.5Ghz is a huge difference ;)

Any chance to fix this?

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WhatsHisName
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Re: N4200 Burst Frequenty (Apollo Lake)

Post by WhatsHisName » 2018/02/15 06:59:55

Good Apollo Lake support in the kernel did not happen until kernel 4.13. EL 7.4 is nominally 3.10 or better for some things.

The EL 7.4 stock kernel performance was terrible on my Apollo Lake ( ASRock J4205-ITX ), but was great using the elrepo kernel -ml.

Try elrepo kernel-ml, currently kernel 4.15 ( http://elrepo.org/tiki/kernel-ml ).

TomvB

Re: N4200 Burst Frequenty (Apollo Lake)

Post by TomvB » 2018/02/15 08:23:19

WhatsHisName wrote:Good Apollo Lake support in the kernel did not happen until kernel 4.13. EL 7.4 is nominally 3.10 or better for some things.

The EL 7.4 stock kernel performance was terrible on my Apollo Lake ( ASRock J4205-ITX ), but was great using the elrepo kernel -ml.

Try elrepo kernel-ml, currently kernel 4.15 ( http://elrepo.org/tiki/kernel-ml ).
Thanks, i'll try it today and post the burst results here.

Update:
Minimum 800Mhz
Maximum 2500Mhz
Thanks for your help! I will use the elrepo kernel.

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WhatsHisName
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Re: N4200 Burst Frequenty (Apollo Lake)

Post by WhatsHisName » 2018/02/15 16:52:14

That is great to hear.

Although it is possible that the needed code will be backported to a future standard EL7 kernel, we may have to wait for EL8 to get relief. The bright side is that the existing EL7 kernels allowed us to (slowly) install the EL7 and then try a different kernel. So often the install on a troubled cpu ends in a kernel panic. :-)

The bottom line with the various Intel ***** Lakes that are having serious problems under EL7 seems to be to "Try kernel-ml." I don't like the idea of running a non-standard kernel, but it is what it is. At least kernel-ml is well supported with updates and we are not using a local one-shot kernel build that gets stale quickly with security holes. My option is to use a different (supported) embedded cpu/motherboard, but I really like the one I have running under kernel-ml ( ASRock J4205-ITX ).

It may not be directly related to kernel-ml, but my sound only occasionally worked under kernel-ml. Creating /etc/modprobe.d/alsa.conf and populating it with "options snd-hda-intel probe_mask=1" followed by a reboot seems to have fixed that problem.

TomvB

Re: N4200 Burst Frequenty (Apollo Lake)

Post by TomvB » 2018/02/15 18:58:51

Yes, true about the security holes etc.
Thanks for the audiofix and explanation. I'll keep it in mind.

This kernel seems to be fine for now.. 8-)

It is a hobby machine and at the moment not stable. (I/O errors / random freezes) I will replace the M.2. ssd asap to test it again. I've also the AcePC (Intel Atom) with Virtuozzo, pretty stable and no problems at all.

Saved me a lot of time, thanks :)

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