[time-nuts] Modern motherboard with RS232 port

[Bob Camp]

Hi

Onboard ethernet on the pi model B is hooked into the CPU via the USB port. That may not be best for accurate time.

Bob


On Aug 19, 2012, at 1:16 PM, bownes <bownes at gmail.com> wrote:

> Why not just use a raspberry pi? Uses a whole 2w at idle. Ntp might bump that  to 2.01. 
> 
> 
> 
> 
> 
> 
> 
> On Aug 19, 2012, at 13:06, Chris Albertson <albertson.chris at gmail.com> wrote:
> 
>> This sounds like a newer version of the board I use.   The thing to check
>> is if the CPU heat sink has a fan or not.  Having no fan indicates that the
>> CPU is not using much power.  It also removes a common failure point.
>> 
>> To reduce power even more.  On an NTP server you can unplug the keyboard,
>> mouse and monitor and if you have other servers on the LAN configure one as
>> a "boot server" and have it run TFTP then your NTP server does not need a
>> disk drive.  It can run off a "RAM disk".  This makes it very fast, even
>> faster than a SSD and it saves some cash.  Makes backup easy too as there
>> is nothing to backup if there is no local storage.  If you don't have a
>> TFTP server use a small notebook size disk drive. Even a 80GB drive is
>> overkill.  You can also boot from a USB thumb drive and run a RAM disk.
>> 
>> It is worth it to look at your electric bill to find how much you pay for
>> power.  Here I'm at $0.21 per KWH.  A full size PC server can use 250W or
>> more.  There are 8760 hours in a year so you get $460 per year to run that
>> 250W PC.  The little Atom will pay for itself in just a few months.  The
>> first time I did that calculation, my "power hogs" where given away.
>> 
>> 
>> 
>> 
>> On Sun, Aug 19, 2012 at 7:42 AM, Stan, W1LE <stanw1le at verizon.net> wrote:
>> 
>>> Hello The Net,
>>> 
>>> For your consideration:
>>> 
>>> The INTEL model DN2800mt ITX mother board uses a ATOM CPU and
>>> draws about 11 watts of AC power when configured as:
>>> (I have not measured DC power yet.)
>>> 
>>> 30 GB OCZ Nocti mSATA solid state drive,
>>> WIN7 pro, 64 bit, USB keyboard and mouse
>>> APEX MI-0008 case.
>>> 
>>> Also has:
>>> parallel port available on mother board, you extend to a connector
>>> RS232 serial port available on mother board, you extend to a connector
>>> a single DC power supply from 11 to 19 V DC.
>>> 1 each PCIe expansion port, I will use with a premium 4 channel sound card
>>> SATA ports available for HDD/SDD,
>>> USB ports are available,
>>> Motherboard sound, and Gigalan.
>>> 
>>> I have not played with NTP, (yet), but it sounds like a decent time nut
>>> technical challenge.
>>> 
>>> My application is for a remote site with only 13V DC power available from
>>> PV/batteries.
>>> Then use fiber ethernet to get off site.
>>> 
>>> The INTEL website would have further details.
>>> 
>>> Stan, W1LE    Cape Cod   FN41sr
>>> 
>>> 
>>> 
>>> 
>>> ZZZZz
>>> 
>>> 
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>> 
>> 
>> 
>> -- 
>> 
>> Chris Albertson
>> Redondo Beach, California
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