[ntp:questions] Red Hat vote for chrony

Charles Elliott elliott.ch at comcast.net
Tue Dec 9 15:20:41 UTC 2014


> Variable speed fans are available now and motherboards support them.
> Tachometer outputs have been around for a long time, and because fans
> use brushless "DC" motors (i.e. synchronous motors with electronics to
> generate the AC) they all have to have rotational phase detectors
> (although it may be done by monitoring the coil current, rather than a
> separate sensor).  Heavy use of these tends to be associated with
> "quiet
> PCs", so the BIOS may well be set for minimal cooling, rather than
> keeping a low temperature.

The biggest problem, IMHO, is that as soon as Windows boots up the fan 
speed goes to 1/2 to 1/4 of its previous speed, and Windows has no control, 
that I know of, to alter that behavior.  Fans are cheap now.  I set the 
BIOS for max fan speed and disable automatic control.

This is a real issue for people who run SETI at Home. Since all of
S at H's applications are heavily optimized, they use all the CPUs, 
all of the logic therein, all the time, and throw off huge numbers 
of BTUs.

Charles Elliott

> -----Original Message-----
> From: questions-bounces+elliott.ch=comcast.net at lists.ntp.org
> [mailto:questions-bounces+elliott.ch=comcast.net at lists.ntp.org] On
> Behalf Of David Woolley
> Sent: Tuesday, December 9, 2014 3:09 AM
> To: questions at lists.ntp.org
> Subject: Re: [ntp:questions] Red Hat vote for chrony
> 
> On 09/12/14 07:06, Charles Swiger wrote:
> > Yes, I also find it a bit surprising than modern desktop CPUs and
> GPUs
> > are willing to run right up to their thermal trip points of ~80 C or
> so
> > rather than bump up fan speed a little more to keep them more around
> 50 C.
> 
> Cost engineering, for what is a throwaway product with a fashion life
> of
> less than 3 years.  Also,
> >
> > Older systems tended to use more aggressive cooling, especially
> laptops.
> >
> > Well, smarter firmware and Hall effect sensors to measure fan speed
> means
> > you can spin the fans more slowly than if you needed to apply 40%
> minimum
> > speed just to be sure that the fan would spin up from idle.
> 
> Variable speed fans are available now and motherboards support them.
> Tachometer outputs have been around for a long time, and because fans
> use brushless "DC" motors (i.e. synchronous motors with electronics to
> generate the AC) they all have to have rotational phase detectors
> (although it may be done by monitoring the coil current, rather than a
> separate sensor).  Heavy use of these tends to be associated with
> "quiet
> PCs", so the BIOS may well be set for minimal cooling, rather than
> keeping a low temperature.
> 
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> questions mailing list
> questions at lists.ntp.org
> http://lists.ntp.org/listinfo/questions



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