[mythtv-users] OT: Hardware purchase question for eventual HD Mythtv system

[Brian Wood]

On Friday 22 May 2009 09:10:07 Johnny wrote:

>
> I recently bought that exact processor from Newegg. It came with a
> heat sink and already had the thermal compound on the heat sink. I
> wouldn't do anything extra. It hasn't run hot. Also if you are making
> purchases with sound considerations in mind, you may want to consider
> getting an aftermarket heatsink that will have a quieter fan. Also
> that 80mm fan that comes with your case is almost guaranteed to be
> really loud. So spending $10-$15 on a quieter case fan like a Scythe,
> can be well worth it. Also if you care about saving energy, the newer
> 80+ certified power supplies can make a significant impact, and there
> are quieter ones available than the one that comes with that case. I
> try to avoid cases that come with a power supply. They tend to be low
> quality and inefficient. A low quality power supply can lead to lots
> of other odd errors or hardware failures that are hard to trace back
> to the power supply. Not to overkill the sound thing, but spending a
> little time to track down a fanless video card is usually worth the
> effort as well.

I, and others, have said it before, but:

The PSU seems to be the first place makers and vendors skimp in order to 
reduce costs. This is in large measure because most users (present company 
excepted) don't know or care much about it.

Any electronics course starts with "pure DC", something rarely encountered in 
the real world of poorly filtered inverter hash, common-mode noise, bad 
grounding and questionable connectors.

Everything starts with a source of good, pure DC, all sorts of bad things 
happen when this is not the case. The efficiency is another important factor.

The way PSUs are rated is incredibly horrible. The total aggregate wattage is 
meaningless in most cases, it's easy to be within the total rated watts while 
overloading one or more of the output rails. Even the makers who state the 
efficiency do so at just one load point (obviously the loading that gives the 
best looking number). The true situation can only be stated as a curve.

The "80 plus" program is a start, but it can also be used to confuse or 
confound the purchaser.

It's well worth the effort and cost to get a good quality power source for 
your machine.

Even well-known (ie: expensively marketed) units can be of low quality. One 
somewhat primitive way to check the overall quality of a PSU is to pick it 
up - if it claims to be a 700 watt unit and weighs only a few ounces, be very 
suspicious. The $19.99 "600 watt" units should also be avoided.

Buying a PSU separately from the case is usually a good idea, obviously a case 
maker is not going to put the most expensive units into their cases. 

There are obviously exceptions to all the rules, but unless you have reliable 
information, the rules-of-thumb are all most buyers have to go by.


-- 
beww
beww at beww.org