[gentoo-amd64] Re: Machine recommendations?

[Duncan <1i5t5.duncan@cox.net>]

Thanasis posted on Sun, 15 Mar 2015 21:44:54 +0200 as excerpted:

> On 03/15/2015 09:08 PM, Leonid Eremin wrote:
>>
>> But here's 2 major cons [of high-power power-supplies]:
>> 1. high power PSUs are less effective at low power usage.
> 
> Maybe if consumption is less than 10% of the PSU's rating, ie less than
> 30W for a 300W PSU.

My ideal would be a reasonably low-power, passively cooled (no fans) 
power supply.  Low power because high power passive-cooling gets 
massively heavy and expensive.  Passively cooled as it's for a router to 
which among other things my VoIP phone adapter connects, which means it's 
going to be on all the time, and thus needs to be silent or nearly so, at 
least at low usage.

On my main machine both the CPU and PSU fans are heat controlled, the PSU 
fan automatically on its own, the CPU fan configured that way in the 
BIOS.  However, while the main CPU fan can actually stop if the temp is 
low enough (in the winter when I first turn on the machine, I get the 
warning buzz for a minute or so as the fan isn't on yet, until it warms 
up, and I have a minimum speed set below which I get a buzz as under 
normal operations it won't be going that slow), the PSU fans don't turn 
down low enough and can bother me if I leave the machine on, say playing 
rain sounds, when I'm trying to sleep.

Which is why I jumped at the idea of having the router play at least 
music-only and still-frame youtube, etc, in an earlier reply, once I saw 
it discussed on that media-player-machine forum.

At some point, I'll probably buy a new PSU for the main machine too, as 
the current one is massively overpowered for the job, but it's what I 
had. (This PSU originally powered my old dual-socket original-3-digit-
opteron machine, which I was at one point running with four spinning-rust 
disks in raid, etc, so it's 850 watt IIRC, while my kil-a-watt says the 
entire system including LED-based TV/monitors rarely tops 400 watt, 
meaning the computer itself should do fine with a 250-300 watt power 
supply, tho I've been going to kil-a-watt check it one of these days to 
see what it actually takes, and haven't yet.)  But meanwhile, if I'm just 
playing stuff like 12-hours-of-rain while I sleep, with the new amd64 
router, I might as well simply use it and turn off the main machine.

But since the router /is/ going to be on all the time, connecting the 
phone adapter if nothing else, I'll definitely want quiet, if not
/entirely/ passive, CPU /and/ PSU heat sink/fans.

For the side of the main machine, I did buy at frys some time ago a big 
8"/200mm fan, 750 RPM, IIRC 110 CFPM, that's close to silent.  Ideally I 
could put something like that in the side of the router to ensure 
reasonable circulation, and go entirely passive on the CPU cooler at 
least.  I know at 250 watt and so they have passively-cooled PSUs as 
well, but I've not looked into it /too/ deeply yet.  I want the thing up 
and running first, and plan on tweaking things like the PSU, if 
necessary, afterward.

But if I can find something reasonably cheap and near enough to silent, I 
might as well get it from the beginning.  Which (besides simply running 
out of time) is the reason I more or less just picked a reasonable case/
psu number and ran with it for that baseline cost estimate.

>> 2. more expensive, after all.
> 
> Not necessarily. Is $45 expensive for a 300W PSU like
> http://www.newegg.com/Product/Product.aspx?Item=N82E16817151113

Well, considering the one case with 250W PSU newegg was offering on 
bundle was $50, $45 for the PSU alone, at a decidedly run-of-the-mill 
300W, is indeed "expensive".

But two things to note about that particular PSU.

1) It's not standard ATX.  It's TFX12V, which since I'm looking at SFF 
(small form factor) cases, may be useful, depending on the case I get, 
but it's definitely NOT the standard power supply most people will be 
most familiar with.  (FWIW, I just looked it up and wikipedia's power 
supply unit (computer) page has a short mention/description of TFX12V 
under "Other form factors", while to the extent it's different, most of 
the page covers ATX.  TFX12V is described as common for small and low-
profile systems like mATX and FlexATX, and some of the smaller mITX 
cases, mITX being the board and cases I'm looking at, may standardize on 
it too.)

https://en.wikipedia.org/wiki/Power_supply_unit_%28computer%
29#Other_form_factors

So it's /not/ a standard ATX power supply, likely accounting for at least 
part of the reason it's $45 for only a relatively low-power 300 watt, 
since TFX12V won't get the same manufacturing volume and thus discounts.

Non-ATX power-supply-cases is part of the additional research I'm doing, 
so when I saw the PSU photo, I immediately picked up on the non-ATX size 
and checked what it was, then looked that up, as I've not memorized the 
various abbreviations yet.

2) This PSU /does/ say "super low fan noise" in the specs, and the 
reviews seem to agree, tho the noise level in dB isn't actually 
quantified for comparison purposes.

I'd be a bit skeptical of the feature claim on its own without an actual 
comparable dB quantification, but the reviews do alleviate my skepticism 
somewhat.  That may be an additional reason for the price.

And of course it's gold-plus certified efficiency, with an 87% efficiency 
number claim.  Again, justifies a bit higher cost.

So all in all, while I've yet to do PSU comparisons and may not need to 
if I buy a case/psu combo, $45 doesn't sound unreasonable, given the 
three points above.  I'll have to keep this one in mind as I do my case/
psu shopping, as it may just fit the bill perfectly if I buy a case 
without bundled supply, that fits TFX12v, not ATX.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman