[Tfug] "Downgrading" ("underclocking?") processors

[Bexley Hall]

Hi John,

On 2/18/2014 9:19 PM, John Hubbard wrote:
> On 02/17/2014 12:11 PM, Bexley Hall wrote:

>> While lots of folks *upgrade* CPU's, does anyone have any
>> experience with *downgrading* a CPU?
>>
>> I think I can replace the "active" cooling in some of the
>> machines I've been looking at for NAS boxen with totally
>> passive cooling *if* I "simply" downgrade the processor
>> in those boxes.
>>
>> I'm interested in any experiences like this.
>
> I switched one of my machines to lower TDP processor. I lost a little
> performance (not really enough to notice), and the system got maybe a
> little quieter.

But, you only "lost" (interactive?) performance because you had
previously established a higher expectation.  If, for example,
you had enough horsepower to process a frame of video in 1/35th
of a second and now require a full 1/30th of a second to perform
the same amount of "work", you've "lost performance" -- but not
in any way that matters (assuming a frame rate of 30fps).

I think there is a difference between machines that you expect to
interact with (where faster always *feels* better) and machines
that are intended to perform a certain task in a certain time
(and, anything faster is just "idled CPU cycles")

> I've gotten bigger gains with higher efficiency fans,
> and CPU coolers. My mini-ITX system is pretty quite. Its running a
> single 120mm fan that is relatively quiet, and a large fanless heatsink.

Fans are out.  They break.  Airflow gets restricted:  intake sucks
something up against the "grill" preventing airflow; fan RPM sensor
still reports fan is spinning but no cooling is happening;  CPU
on-die sensor reports temperature of CPU -- but not of anything
else in the box (CPU can be idle yet video controller is still
moving pels to the screen at the same rate it always was).

My goal is to have a design that doesn't crap out because something
blocked an intake (fur balls/dust bunnies clogging an input filter)
or a fan gave up the ghost, etc.  (come home to find CPU has *melted*
and everything it was expected to do in your absence didn't get done!)


Time to squeeze oranges.  Damn winter has been way too mild -- already
have next crop started and haven't picked *last* crop!  :<