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Re: [vox-tech] looking for a new video card
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Re: [vox-tech] looking for a new video card



Speaking of which, luck you, you have triggered one of my rants.... I know
there's so many to pick from.

Cooling, such a simple idea... done so poorly.  Move air over something and it
cools.  If you care about noise the bigger the better.  Basically a 120mm fan
will be quieter than a 25mm fan for the same volume of air.  Reliability seems
to scale with size as well.

My favorite fan for PCs is 120mm mostly because that seems to be the largest
fan where you can find a large variety of fans to insure you can find one that
meets your needs.

Fans are pretty simple, the higher the pressure they have to push against the
less airflow there will be.

Now the PC failures:
* tiny fans suck, GPUs and motherboards should never have tiny fans
* any system should have a nice designed airflow, none of this
  any component might blow air in any direction
* the hottest components should have the best airflow.
* Heat given the chance would prefer to rise.

And the biggest serving of FAIL... graphics cards, in fact it's hard to
imagine them getting it more wrong.  High end GPUs take dramatically more
power than high end CPUs.  The CPU typically enjoys a nice healthy airflow
from the bottom front of the case, and exhaust through the top rear exhaust
and the top rear power supply. GPUs on the other hand form a cube with only
one side open trapping air that it tries to dump lots twice the CPU) of heat
into.  To top it off they often have tiny fans.  Since there's no engineered
airflow over the GPU it often depends on the various fans/speeds.  Sometimes
the front fans are stronger... overwhelm the rear fans and sneak out past the
GPU.... of course sometimes the rear fan+power supply are stronger, and suck
air in past the GPU... which unfortunately can cause a loop, hot air out the
top rear of the case then gets sucked in past the GPU again... especially bad
if it's under a table.

So what would a better case look like:
* 120mm or larger fans on the front
* adjustable exhausts, making it easy to balance GPU and CPU cooling
* no fans on any component (mostly CPU heat sink, video card, and
  motherboards)
* either an adjustable vent below the GPU or a gpu with the heat sink on top.

Of course folks might thing servers are better... and they are inside the
node, but really suck for a rack full of them.  Sure it's front to back, but
often with 6-12 small fans per 1U, 240-480 per rack... all achieving a rather
unspectacular airflow and often an impressive amount of noise.  Not to mention
a significant fraction of the entire power load (often over 10Kw) is used for
airflow.  If they ditched the 240-480 fans they would have a more open node,
and could use a few 20" fans at the rear of the case, like 2-3.  At one point
I had a rack that ran really hot, I just put a single box fan behind the rack
and blew upward (again the heat likes to rise thing) and it had a radical
effect node temps, where the entire nodes were hot the the touch after the fan
only they very rear edge was warm.

*deep breath*

So, the best I've found out there is the antec P180/182 for a desktop.  Good
airflow, easy to get even aggressive systems pretty quiet, separate airflow
for the power supply and drives.  It's an ideal case for a passive cpu cooler,
within 1" or so of the CPU heat sink there's not 1 but 2 120mm fans, each
settable to 3 speeds.

As for servers... well you can buy blades, at a large price premium... but
that's really the only alternative I've seen.  Nobody sell's 1Us without a ton
of tiny noise fans in them.
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