Re: RedHat 5.0 and Power Supply.

[Zoki <zokiphoto magic fr>]

On Fri, 2 Oct 1998 hyprreal cdc net wrote:

->At 01:08 AM 10/2/98 +0200, you wrote:
->>On Thu, 1 Oct 1998 hyprreal cdc net wrote:
->>*** Does the ventilo slow down when you start a program (when the CPU
->>works) and speed up when the computer (the CPU) is idle!??
->>
->>Zoki.
->>
->>Mailed with Linux and Pine.
->>
->>
->
->	Yes... Is there a way to correct this?


*** Daniel,

I don't have *the solution* but I can maybe explain what the reason is and
how we solved it. It's something I read about some time ago and we had
the same problem in our office.

It seems that Linux is able to switch off the CPU when it's not used, thus
freeing the power supply due to which the rest gets more power. I guess
the HD's have a power regulator but the effect on the ventilo's is that
they make substantial noise due to speeding up and slowing down. The
problem doesn't apply to Win 95 because it doesn't control the CPU unless
you put it on standby. The test we did was to use a little program written
for the Cyrix CPU's that did the suspending thing on Win 95 and the result
was that you could indeed hear the whining of the ventilo's going up and
down. It has something to do with the wireing of the power supply. We ended
up mounting the power supply outside of the box in such a way that the side
of the supply where the DC power cables come out is the side mounted
against the PC box, the DC cables being long enough to connect to the
hardware without problems. We took the ventilo of the power supply out and
changed the top cover of the supply with a pierced one so the inside cools
off with the surrounding air. The power supplies ventilo is sucking air out
of the box now and with the 2 extra ventilo's added (one sucking air in at
the level of the CPU and the other one in front of the HD's) the box is
running very cool, the noise has been reduced with factor 2 and the
spinning up/down of the ventilo's isn't noticeable anymore. BTW, the CPU
ventilo is also on half speed.

I have to admit we didn't solve the core of the problem - we couldn't,
even after spending a few days on it - but did it this way and
additionally found a very simple way to silent the machines down to almost
zero noise. Since we're working with 5 designers in a small office the
noise issue was always a problem. Just to finish off this - just in case
somebody is interested - we did the finishing touch in silencing the PC's
by "hanging up" the HD's and avoiding direct contact with the case. This
reduced vibrations and noise drastically.

I'm sorry I can't give you a magic solution, but the above solution worked
for us and it might give you an idea.

Lots of luck,
Zoki.

Mailed with Linux and Pine.