# Guidance for powerd and new CPUs



## FzZzT (Sep 16, 2016)

I've gotten three machines in the past few months (all returned) which didn't work with the latest FreeBSD and powerd. I'm trying to find fanless a low-power system for a firewall box that I can lower the speed on in order to drop the power/temp/etc. even more. Ideally it would use like 5W and run cool to warm to the touch--a heat sink is okay but not if it runs at 100F and draws 30W when idle. It's not going to do much most of the time, but it will be powered on all the time.

Unfortunately all the machines I've tried lately have not been supported by powerd or FreeBSD (no cpufreq support in the kernel, or something). Either the CPUs don't have C states _or_ multiple frequencies don't show up _or_ they do show up but they simply don't work _or_ they show up and seem to work but don't affect heat or power usage...

Is there any way to determine if the chip supports this stuff _before _I buy it? Or does anyone have recommendations that they know work for this purpose?

(I did try a EdgeRouter, but it was a big pain to deal with, so I sent that back also.)


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## Crest (Sep 19, 2016)

Without support for hardware offloading the EdgeRouter Lite is just a curious MIPS64 board. It has working FreeBSD support, but the real power of the octeon platform as a router and firewall is in its offloading engines of which FreeBSD supports only the crypto engine.

An APU2C4 board should fulfil your requirements.


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## FzZzT (Sep 19, 2016)

Thanks for the recommendation. I ordered one of these last week and will see how it goes:

https://www.zotac.com/us/product/mini_pcs/ci521-nano

It's only 4.5W TDP and (according to Intel) the CPU supports EIST and idle states. If it doesn't work out I'll give your board a try.


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## kpa (Sep 19, 2016)

You really want a CPU that supports EIST now to have efficient power throttling. The reason why powerd(8) is not working is usually a CPU that has no EIST support and FreeBSD by default now disables the throttling features such as p4tcc and acpi_throttle that are considered redundant and deprecated:

https://wiki.freebsd.org/TuningPowerConsumption


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