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by danford 4442 days ago
I love FreeBSD and was planning on switching some servers from Linux but found that it consumed about 25% more power than my Linux boxes (even after extensive power management tweaks) and in the end didn't have much advantage.

It's not hard to install freeBSD in a VM, set up ssh, run it headless, and ssh in. I suggest you give it a go. It's a great learning experience.
2 comments
networked 4442 days ago
>I love FreeBSD and was planning on switching some servers from Linux but found that it consumed about 25% more power than my Linux boxes

Wow, I wouldn't have thought there would be such a dramatic difference in power consumption on anything but portable hardware. Did you try to measure the CPU and I/O usage on your servers and compare them between Linux and FreeBSD? I wonder if FreeBSD's greater power draw was due to its ACPI implementation or if the average system load was also higher (ZFS?).

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danford 4442 days ago
I wasn't using zfs at the time and I didn't do much comparison with CPU and IO, I used a wattage meter. I followed the FreeBSD guide (http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/ac...) and tried just about everything. My Linux box was running at about 9watts (idle) and freeBSD started out at around 18, but I got it down to about 12watts after making a lot of optimizations.

I think most of the difference is because FreeBSD is using older more stable software, and the Ubuntu server was running some of the latest software.

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takeda 4442 days ago
Do you remember which FreeBSD version and which Linux kernel version was it?

Linux had tickless kernel + CPU scaling for a while. FreeBSD is lagging in this aspect.

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profquail 4441 days ago
The FreeBSD kernel is tickless as of FreeBSD 10:

http://www.freebsdnews.net/2013/09/20/freebsd-10s-new-techno...

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takeda 4441 days ago
Yes, exactly, it only has it for couple of months, that's why I asked about version.
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mfb 4442 days ago
I'd be interested to see some benchmarks comparing Linux and FreeBSD power usage. Personally I've been impressed w/ power management on FreeBSD 10 using recent hardware - once I enabled powerd and set the powerd_flags - but I haven't installed Linux on the same hardware.
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