[time-nuts] Testing frequency using NTP

Poul-Henning Kamp phk at phk.freebsd.dk
Mon Nov 3 08:51:27 UTC 2008


In message <490E4F2C.30201 at wwrinc.com>, "David M. Witten II" writes:

>Can I still expect to see similar performance using more recent versions 
>of FreeBSD than you originally used?

Yes, the timestamping is done in hardware, so it does not depend on
the OS version.

>Will a usable build of FreeBSD 7.x run in the memory available on the 
>older Soekris boards? (64 MB RAM)

Absolutely.

>I understand that there are features that made boards incorporating the 
>133 MHz AMD ElanSC520 processors suitable for this purpose.  Are these 
>features still present in the newer AMD Geode LX based boards?

No.

>Though I know that you have worked with Soekris products a lot, is there 
>any reason that the same techniques cannot be applied to the WRAP and 
>ALIX boards from PCEngines?  or perhaps an One Laptop Per Child (OLPC) XO?

It all comes down to the special counter hardware in the Elan520 CPU,
any board with an Elan520 where you can get at the timer1 pin is fine.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.




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