gpsd-users
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Clarifications about PPS SHM content


From: David J Taylor
Subject: Re: Clarifications about PPS SHM content
Date: Mon, 30 Mar 2020 14:05:29 +0100

Hi!

I ran a test with ntpheat for a day, and my jitter StdDev jumped from
~275ns to ~700ns. For my setup, it's NOT better.

I'll see if my physical "mod" will help: I stuck two layers of sticky
thermal pads on top of each other, covering both the CPU footprint and
the crystal, on the underside of the CPU. My idea is to better conduct
heat from the CPU to the crystal while reducing heat transfer transfer
to air. The pads have better thermal conductivity than air, but being on
top of components like a blanket should provide some isolation to air.
Heat should spread a bit better between nearby components and the PCB,
but I have nothing on top to wick heat away. If I had thicker pads (mine
are pretty thin), I'd try to put a piece of metal to spread heat across
the whole area.

My CPU usage is already 25%x4 cores, there is some heat there. I just
have to stabilize it across the xtal and prevent too much air movement.

I will report back later!

Martin
=========================================

Thanks for your initial report, Martin! I look forward to further tests. In the light of your tests, I've updated my Web page to indicate that it's not a cure-all, rather a try-it-and-see solution.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: address@hidden
Twitter: @gm8arv


reply via email to

[Prev in Thread] Current Thread [Next in Thread]