[mythtv-users] Adventures in upgrading my MythTV hardware

[Will Dormann]

On 10/17/18 2:56 PM, Will Dormann wrote:
> 
> In case anybody's feeling crafty and wanting to slow (quiet) down one of
> their system fans, I've added a brief description and pictures of what I
> did at the end of my case review here:
> https://www.amazon.com/gp/customer-reviews/R3RST3X7YWW59Z


One more update in my quest for a really quiet MythTV system, in case it
helps others:

The zener diode trick worked quite well.  But I still noticed a bit of
fan rattle.   That, combined with my lack of confidence in the PSU
quality (it's suspiciously lightweight and empty-looking), I ended up
purchasing a high-efficiency PSU that is truly fanless.

Here's the thing about anybody aiming for a silent combined FE/BE
system:   Once you get rid of the most-noticeable noise, that'll leave
you noticing the second-most-noticeable noise.   In my case, I still
have a CPU fan and a case fan.    It's definitely better than before.
But not silent.

On the upside, the new PSU (80+ Platinum rated) results in not only a
quieter system, but one that draws less power.  My original numbers:

> As for power usage, it's more than the ION system, but I think it's a
> reasonable trade-off for a system that is so much more functional.
> Plugged in, but powered off: 6W (Wait, what?)
> Idle: 44W
> Watching TV: 49-55W
> Max CPU load: 59W


My new numbers:

Plugged in, but powered off: 1-2W
Idle: 31W
Watching TV: 35W
Max CPU Load while watching live TV: 58W


Which is an improvement.  But if you run some numbers, you'll realize
that it'll take over 10 years to recoup the cost of the new PSU.

In the end, the system is nicer than it was before the PSU swap.  And
I'm much more confident that the new PSU will last much longer than the
old one would have.  But I somewhat question whether it was worth the
money/effort to make the switch.

Lessons:
 - Beware of going down the path of pursuing a silent combined MythTV
system.  Sure, you can swap out parts for more quiet ones.  But I
suspect that until your system has *zero* moving parts, you may end up
going down a path of replacing more parts and spending more money than
you expected.  Even with zero moving parts, you may end up with a slight
buzz if you put your ear close (e.g. 60Hz in the US)
 - Parts that draw little current are nice for the power bill.  But
before replacing any parts just for the concept of using less
electricity, be sure to run the numbers to see exactly how much money
you may be saving per year.  In my case, I didn't swap out the PSU for
the power efficiency.  Just the noise level.  But the increased
efficiency was just an added (not-cost-effective) bonus.



-WD