Poor Newegg Review For Gigabyte PS Gets Funny Response FromManufacturer

Dave C. wrote:
I'm not sure if there was any specific reasoning as to why they
started off putting them on top in the first place, but *that*
decision seems a little odd.

Many computers were cooled with only one cooling fan. That is the one
that was mounted on the back of the power supply. Air would be pulled
through the case, then through the power supply, then exhausted out the
back of the power supply. Therefore it made sense for the bottom/back
of the PSU to be mounted as high as possible in the case. That's the
direction all the hot air was going anyway, so it made cooling more
efficient to have the PSU way up top.

The PSU still assists somewhat in cooling the case...and more
importantly the components in the case. The only advantage to having
the PSU bottom mounted is that the PSU fan will be drawing more cool
air into the PSU itself. In turn, this means you need a ****load of
airflow to cool the case (and components like the northbridge, CPU and
GPU in particular), because much of your cool intake air is now going
down low where it's not cooling a damned thing. -Dave


There is an equation, to work out what a ****load is.

CFM = 3.16 x Watts / Delta_T_degrees_F [ Formula for case cooling ]

If the entire contents of the computer case dissipated 200W
(components and PSU waste heat), and you wanted to meet the
"well cooled" criterion of 7C difference between case and
ambient (7C = 10F), then the equation gives you

CFM = 3.16 * 200 / 10 = 63.2 CFM

That amount of air can be moved by a single fan.

If you allow a larger delta_T, it means the components in the case
will have a hotter environment to work in, your hard drive gets
warmer and so on. You don't have to shoot for 7C if you don't want to.

Paul

"kony" wrote in message
...
On Sun, 20 Dec 2009 08:42:35 +0800, "Dave C."
wrote:


I think it is wrong to put the power supply in the bottom of an ATX
case. It's just plain stupid to design a box that most customers
will have a problem with. -Dave

Wrong... Why? Other then the cable length issue, what's your
objection?

You need a ****load of extra fans (adding extra noise) to
counter-balance the fact that much of your cool intake air is going in
the wrong direction to cool anything. -Dave


Cases these days, at least anything decent besides this
factor, tend to have more than enough fan mounts... unless
someone is building a higher end gaming system.

Regardless of where the PSU exhausts, as long as there is
one low RPM 120mm fan at the top rear it is enough for the
typical PC.

That is, beyond where the PSU is, the same arrangement as
any other case. Only other fan needed might be right
across from the video card if someone has particularly hot
running (esp. overclocked) card(s), unless the system is in
a particularly hot environment in which case another fan
would be prudent no matter where the PSU is located.



The one exception I might take to that is where an intake
fan might be needed to overcome the resistance of a filter
and still supply a good flow of air for cooling hard drives.
This will usually only be a factor in extreme/dusty
environments.

Luck;
Ken

In message "Dave C."
was claimed to have wrote:


I think it is wrong to put the power supply in the bottom of an ATX
case. It's just plain stupid to design a box that most customers
will have a problem with. -Dave

Wrong... Why? Other then the cable length issue, what's your
objection?

You need a ****load of extra fans (adding extra noise) to
counter-balance the fact that much of your cool intake air is going in
the wrong direction to cool anything. -Dave

A "****load"? One 120mm fan will push more air then a 80mm (or even
120mm) which needs to push air through the PSU.

In addition, you get lower average temperatures, so your fans (both on
the PSU if it's temperature regulated) and the one you install at the
top of your case can run at lower RPMs.

On Sun, 20 Dec 2009 19:37:57 -0600, "Ken Maltby"
wrote:


That is, beyond where the PSU is, the same arrangement as
any other case. Only other fan needed might be right
across from the video card if someone has particularly hot
running (esp. overclocked) card(s), unless the system is in
a particularly hot environment in which case another fan
would be prudent no matter where the PSU is located.



The one exception I might take to that is where an intake
fan might be needed to overcome the resistance of a filter
and still supply a good flow of air for cooling hard drives.
This will usually only be a factor in extreme/dusty
environments.

Luck;
Ken


I wouldn't really call a case design very good if the filter
panel is both restrictive enough and small enough it needs
the additional fan to overcome filter resistance, but I
would still want a front intake fan behind the filter panel
so the case is positive pressurized to the extend it pulls
most air through that filter panel instead of the little
gaps elsewhere.

On the other hand, one case I set up with a filter panel I'd
added, I had doubts whether the user would clean the filter
panel as often as it should be so I left the case negatively
pressurized with most of the air being filtered but if the
filter were to get clogged it doesn't completely starve the
system, at that point a higher % of air coming through the
cracks is better than nothing (and relatively it was a low
power, energy conservative system).

On Dec 18, 3:30*pm, ShadowTek wrote:
I had a bad experience with a Gigabyte power supply that I bought from
Newegg, so I posted a review of it reflecting my opinion of it. The
manufacturer's response seemed humorous, so I thought you might
enjoy it.http://www.newegg.com/Product/Produc...82E16817233010

Like another posted earlier, you indeed were fortunate enough to have
your review posted by Newegg. I had mine rejected for posting that the
item was defective. At least they had the decency to reply back and
tell me this was the reason.