VA-20 Report & Thanks

All,

Just wanted to drop a line and say Thanks!

I had a eMachine die, and I thought I'd try a "inexpensive" rebuild, or
decide if I should just part it out. Orig machine was a T2865, with a
Athlon 2800+ XP, 512 MB of RAM + a large HDD and 8X DVD/RW. Nice stuff
to toss, so I picked up a VA20 for $55.00 @ Frys.

Initial build went fine, laid down Win 2K and applied all drivers from
the CD. Visisted M$ for SPs+ Misc fixes. Half day in, the thing belly
flops, and wont get past POST. I READ every article in ths group, and
finally got to one that discussed adjusting the FSB from dflt setting of
133 to 166. All good after that, but HDD got toasted somehow (logically,
not physically), so a extra HDD was subbed in, and a fresh OS install
done. Seems quite stable after that. Reattached the former 160GB
toasted HDD, and reformatted. Looks good so far.

Interestingly, while I changing the FSB setting, I had also removed a
older Hercules Prophet AGP card during the diags process. I dont know if
that was a player in the problem, but after I have this up for a while
and stress it a bit, I will reinstall the AGP card and see if it
introduces any issues.

All in all, for the cost, the board seems to be a good 'value' board.
Since I was placing it in a eMachine frame, it was the only ones at Frys
that would fit the propietary case, at a good price point.

Most issues I read on the net suggested the 2 most promient failure areas
in eMachines is the MoBo and Power Supply. When build this anew, I
introduced a new PS I has lying around, but only a 250W model, which is
what was in it before. The old PS is good, and I'll hang on to it, but
how does one guage when a PS is inadequate? Most advise to simply go
huge, but that is more $, and likely would introduce more heat, something
I may already have to deal with if I include the AGP card (and I'm still
running 2 WD HDDs currrently, up from 1 before.

To all that help here, and leave trails of bright ideas, Thank You!

 

Snipped:

Try:

http://www.jscustompcs.com/power_supply/

MikeE

 

: All,
:
: Just wanted to drop a line and say Thanks!
:
: I had a eMachine die, and I thought I'd try a "inexpensive" rebuild, or
: decide if I should just part it out. Orig machine was a T2865, with a
: Athlon 2800+ XP, 512 MB of RAM + a large HDD and 8X DVD/RW. Nice stuff
: to toss, so I picked up a VA20 for $55.00 @ Frys.
:
: Initial build went fine, laid down Win 2K and applied all drivers from
: the CD. Visisted M$ for SPs+ Misc fixes. Half day in, the thing belly
: flops, and wont get past POST. I READ every article in ths group, and
: finally got to one that discussed adjusting the FSB from dflt setting of
: 133 to 166. All good after that, but HDD got toasted somehow (logically,
: not physically), so a extra HDD was subbed in, and a fresh OS install
: done. Seems quite stable after that. Reattached the former 160GB
: toasted HDD, and reformatted. Looks good so far.
:
: Interestingly, while I changing the FSB setting, I had also removed a
: older Hercules Prophet AGP card during the diags process. I dont know if
: that was a player in the problem, but after I have this up for a while
: and stress it a bit, I will reinstall the AGP card and see if it
: introduces any issues.
:
: All in all, for the cost, the board seems to be a good 'value' board.
: Since I was placing it in a eMachine frame, it was the only ones at Frys
: that would fit the propietary case, at a good price point.
:
: Most issues I read on the net suggested the 2 most promient failure areas
: in eMachines is the MoBo and Power Supply. When build this anew, I
: introduced a new PS I has lying around, but only a 250W model, which is
: what was in it before. The old PS is good, and I'll hang on to it, but
: how does one guage when a PS is inadequate? Most advise to simply go
: huge, but that is more $, and likely would introduce more heat, something
: I may already have to deal with if I include the AGP card (and I'm still
: running 2 WD HDDs currrently, up from 1 before.
:
: To all that help here, and leave trails of bright ideas, Thank You!
:
:
:
: --
: Does anyone really read these?

Yes

 

You inundate me with your verbosity !!!


Qed.

PS- You forgot the 'period' ... [.]. <VBG>

 

Qed wrote:
|
| You inundate me with your verbosity !!!
|
|
| Qed.
|
| PS- You forgot the 'period' ... [.]. <VBG>

He's still waiting for his share of periods.

The shortages due to your OPEC (Organization of Punctuation Exporting
Countries) Embargo haven't been relieved by adequate supplies in all parts
of the country, even with the higher retail prices.

Jef

 

<<snip>>

There is another PSU estimator here. This one attempts to work
out the current required on each output rail. The label on the
side of the PSU shows how much current is available on each
output voltage, and that is a better indicator of performance
than the simple-minded total power figure.

http://takaman.jp/D/?english

Some things to watch for. The main emphasis on one of these
calculations, is where does the processor draw its Vcore
current from. Asus AthlonXP motherboards tend to use the
+5V rail, while other vendors may use the +12V rail. If a
motherboard uses the 2x2 ATX12V power connector, that is
a sure sign that the motherboard uses +12V to power the
processor.

Say a processor draws 60 watts. If the processor power comes
from the +12V rail, then that is 5 amps from +12V. If instead,
the +5V rail is used, that is 12 amps from +5V. In other words,
in both cases the power is 60 watts, but as the supply voltage
used drops, the current needed increases. To that figure, you
also have to include an efficiency factor for the Vcore circuit.
The Vcore converter on the motherboard, could be 90% efficient,
which means an extra bit of power from the PSU is wasted. The
required current increases by 1 / 0.90 or 1.11 times as much.

Taking the 60W processor as an example, if the +12V rail is
used to power the processor, the current needed is
(60 / 12) * 1.11 = 5.55 amps.

When you use the Takaman page, you may need to move the processor
current consumption contribution, between the +5V and +12V columns.
Keep the above math in mind, when moving the numbers from one
column to the other. (I.e. 5.55 amps in the +12V column, becomes
13.3 amps in the +5V column.)

If I wanted a "barely adequate" power supply, suitable for
any motherboard with a less than $200 processor installed in
it, I would want 12V @ 15 amps and 5V @ 25 amps. The large
5V rating, covers those AthlonXP motherboards that draw virtually
everything from +5V. The 12V rating is sufficient for your
run of the mill 3GHz Pentium4 processor. For 3.3V, I'd go for
at least 20 amps, but usually it isn't a problem getting that
from the power supply (once the other rail requirements are met,
usually the 3.3V will be pretty big also).

Here is a table of Antec Truepower supplies. All of these
meet the requirements for a basic system, so even the 330W
version would suffice. Of course, you can still run the
detailed calculation on Takaman or jscustompcs, to make
a more precise (and cheaper) selection.

VOLTAGE +5V +12V +3.3V -5V -12V +5VSB
TRUE330 30A 17A 28A 0.5A 1.0A 2.0A <-- Good enough...
TRUE380 35A 18A 28A 0.5A 1.0A 2.0A
TRUE430 36A 20A 28A 0.5A 1.0A 2.0A
TRUE480 38A 22A 30A 1.5A 1.0A 2.0A
TRUE550 40A 24A 32A 0.5A 1.0A 2.0A

The jscustompcs estimate for RAM power seems to be a little
on the high side, but it probably doesn't matter that much.

On the heat side of things, the heat thrown off by the
power supply, is a function of its conversion efficiency.
I think the ATX spec mentions 68% efficiency as the minimum,
and some of the better supplies now manage 80% efficiency.
For 100 watts of output power, the 68% power supply throws
off 47 watts of heat. (100 / (100+47) = 68%). The second
example throws off 25 watts of heat ( 100 / (100+25) = 80%).
The more power you draw from the PSU, the more heat it
throws off internally.

If you want to select a PSU based on its efficiency, Tomshardware
had a recent review with some listed numbers. Your typical usage
pattern will range somewhere between the "light" and "medium"
ratings. A PSU that does well for both of those cases, is what
you would want. The "Zippy" supply, by the way, is $185 at Newegg,
so is not a cheap supply. The Enermax is also expensive. The
Fortron Blue Storm is $90. If your objective is efficiency,
perhaps that is a good choice (read the review comments on Newegg
before buying). I don't know if any lower total power supplies
have good efficiencies like the top runners in the Tomshardware
article.

http://www.tomshardware.com/howto/20050228/power_supply-37.html

HTH,
Paul

 

Tell him to Go Arab, get himself a bevy of wives and girlfriends, and
he'll have all the periods he can stand.

 

Brian Brunner wrote:
|
| Tell him to Go Arab, get himself a bevy of wives and girlfriends, and
| he'll have all the periods he can stand.
|

Nice pun.

Jef