Power requirements

I want a new silent (or quiet) PSU. Is there a way to figure out what size
power supply I need?? How many watts does a motherboard, chip, memory etc
use?? I have:

Soltek SL75-DRV5. Athlon XP2400+. 2 memory modules (512+1024).
AGP - radeon 8500
PCI - 4 cards: rj45 card. 802.11b card. SCSI card. 5.1 sound card.
No floppy
3 hard disks - IBM 10GB + Maxtor Diamond Max 60GB + 6.4GB (removable caddy -
not in much)
DVD drive
CD writer (scsi)
2 case fans + 1 zalman 90mm fan.

I think that is everything.

> I want a new silent (or quiet) PSU. Is there a way to figure out what size
> power supply I need?? How many watts does a motherboard, chip, memory etc
> use?? I have:
>
> Soltek SL75-DRV5. Athlon XP2400+. 2 memory modules (512+1024).
> AGP - radeon 8500
> PCI - 4 cards: rj45 card. 802.11b card. SCSI card. 5.1 sound card.
> No floppy
> 3 hard disks - IBM 10GB + Maxtor Diamond Max 60GB + 6.4GB (removable
caddy -
> not in much)
> DVD drive
> CD writer (scsi)
> 2 case fans + 1 zalman 90mm fan.

I used to run my Dual AthlonMP on a cheap "Sparkle" brand 300- or 325-
watt power supply. I finally did get the machine to overload the power
supply, but I had to have both chips fully loaded, both hard drives running,
be reading from the DVD-ROM, *and* burning a DVD on the other drive all at
the same time. Unless I did all of that at once, it would run like a champ.

If you have a power supply of decent quality, then it actually takes a
*very* serious rig to overload even a 300 watt power supply - dual
processers, peltiers, or a combination of an extremely high-draw CPU and an
extremely high-draw video card. So assuming that the power supplies you're
looking at are of decent quality, and are at least 300 watts (anything
larger would just be to hedge against future upgrades), then you won't run
into any trouble with that machine.

In fact, I've got a good number of dual-Xeon and dual-AthlonMP machines
at work, and it's rare for any of them to have a power supply larger than
350 watts - even those with multiple SCSI drives and a hardware RAID card.
I do have two machines that would *NOT* run on a 400-watt power supply, but
they both have 4 processers and 4/10 SCSI disks, respectively. : )

steve

Gareth Tuckwell wrote:
> I want a new silent (or quiet) PSU. Is there a way to figure out what
> size power supply I need?? How many watts does a motherboard, chip,
> memory etc use?? I have:
>
> Soltek SL75-DRV5. Athlon XP2400+. 2 memory modules (512+1024).
> AGP - radeon 8500
> PCI - 4 cards: rj45 card. 802.11b card. SCSI card. 5.1 sound card.
> No floppy
> 3 hard disks - IBM 10GB + Maxtor Diamond Max 60GB + 6.4GB (removable
> caddy - not in much)
> DVD drive
> CD writer (scsi)
> 2 case fans + 1 zalman 90mm fan.
>
> I think that is everything.

You can use this power calculator to get a *rough* idea of what size PSU
you need.
http://www.jscustompcs.com/power_supply/

> You can use this power calculator to get a *rough* idea of what size PSU
> you need.
> http://www.jscustompcs.com/power_supply/

Wow. Interesting that the place selling the parts is the one telling you
how big of a PSU you need. Their numbers for some devices is a lot higher
than actually needed. I took some small machines we have at the office, and
plugged their config into the calculator, and it said that I needed a
minimum power supply of 195 watts. These machines came with *100* watt
power supplies, and work just fine.

So, for fun, I plugged in the specs for the machine I'm on right now.
Yep, it came out with a figure significantly greater than the power supply
I'm currently running on - and I know for a fact that the power supply I'm
on still has some room left in it.

But wait, there's more! I plugged in the specs for my file server, and it
came up with a figure pretty much equal to the P/S that's in the machine -
but that machine doesn't come anywhere *close* to using the full potential
of the P/S.

As always, question advice from people who stand to make financial gain
from your decision.

steve

On Thu, 9 Sep 2004 14:24:49 -0400, "ICee" <>
wrote:

>Gareth Tuckwell wrote:
>> I want a new silent (or quiet) PSU. Is there a way to figure out what
>> size power supply I need?? How many watts does a motherboard, chip,
>> memory etc use?? I have:

>> Soltek SL75-DRV5. Athlon XP2400+. 2 memory modules (512+1024).
>> AGP - radeon 8500
>> PCI - 4 cards: rj45 card. 802.11b card. SCSI card. 5.1 sound card.
>> No floppy
>> 3 hard disks - IBM 10GB + Maxtor Diamond Max 60GB + 6.4GB (removable
>> caddy - not in much)
>> DVD drive
>> CD writer (scsi)
>> 2 case fans + 1 zalman 90mm fan.

>> I think that is everything.

>You can use this power calculator to get a *rough* idea of what size PSU
>you need.
>http://www.jscustompcs.com/power_supply/

or ....
http://www.antec-inc.com/pdf/article...Article1.html#

BoroLad

"Steve Wolfe" <> wrote in message
news:...
>> You can use this power calculator to get a *rough* idea of what size PSU
>> you need.
>> http://www.jscustompcs.com/power_supply/
>
> Wow. Interesting that the place selling the parts is the one telling you
> how big of a PSU you need. Their numbers for some devices is a lot higher
> than actually needed. I took some small machines we have at the office,
> and
> plugged their config into the calculator, and it said that I needed a
> minimum power supply of 195 watts. These machines came with *100* watt
> power supplies, and work just fine.
>
> So, for fun, I plugged in the specs for the machine I'm on right now.
> Yep, it came out with a figure significantly greater than the power supply
> I'm currently running on - and I know for a fact that the power supply I'm
> on still has some room left in it.
>
> But wait, there's more! I plugged in the specs for my file server, and
> it
> came up with a figure pretty much equal to the P/S that's in the machine -
> but that machine doesn't come anywhere *close* to using the full potential
> of the P/S.
>
> As always, question advice from people who stand to make financial gain
> from your decision.
>
> steve
>
>

There is a lot more to consider than just the total wattage of the power
supply.

Soltek SL75-DRV5.
(this board uses more amps from the 12v or from the 5v lines and how many
amps from each?)
Athlon XP2400+.
(i know for a fact that the AMD XP will consume most of its power from the
12v line ~68w under load that's about 5amps)
2 memory modules (512+1024).
(you can figure about 5w to 7w per 128MB's again under load most of the
power will come from the 5v line ~10amps)
AGP - radeon 8500
(if I remember correctly the older ATI cards draw about 50/50 from the
5v/12v lines mem/cpu under load ~ 4amp/4amp)
PCI - 4 cards: rj45 card. 802.11b card. SCSI card. 5.1 sound card.
(i dont know what voltage line the above cards use you will have to look it
up and use Voltage * current(amp) = Power (watts) and determin the amperage
draw from each line.)
No floppy
3 hard disks - IBM 10GB + Maxtor Diamond Max 60GB
(most hard draw there power from the 5v and 12v lines with the majority
coming from the 12v line)
DVD drive
CD writer (scsi)
2 case fans + 1 zalman 90mm fan.
(power requirements for fans are written on the back of the fan and pull all
there power from the 12v line ~ 0.3 amps per fan)

You need to determine the following,
amperage draw on the 12v line
amperage draw on the 5v line
amperage draw on the 3.3v line
and then determine percent of usage as i am sure that you will not be using
all the HD at the same time or be constantly stressing the CPU at full load.
Will you be overclocking the system (cpu, fsb) overclocked system will use
more power (increased voltage increases power req.).

Once you have determined the power on each voltage line select a PSU which
will provide the needed current to each voltage line at a stable rate
because not all power supplies will produce what they are rated for look for
a good name brand.

Just a quick look at the system you have it appears that you will need at
least 16amps on the 12v line and 18amps would be better. The key word he is
stability, fluctuating voltage destroys electronic components and produces
instability although it may not be evident at first. It may take a few
months to appear as system components start to breakdown.

AMD web site has a power cal sheet that could help.
http://www.amd.com/us-en/assets/cont...docs/26003.pdf

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


--
Ed Light

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MS Smiley :-\

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Thanks, robots.

On Thu, 9 Sep 2004 19:15:24 -0700, "Ed Light" <>
wrote:

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

Best one yet Ed !
BoroLad

Rusty wrote:
[...]
> Athlon XP2400+.
> (i know for a fact that the AMD XP will consume most of its power
> from the 12v line ~68w under load that's about 5amps)

This is incorrect. The motherboard, not the CPU, decides where the CPU gets
its power from. In the case of the Soltek 75DRV5, I'm pretty sure it's fed
from the 12V rail. However, for many (especially older) AMD boards the CPU
regulators are fed entirely from the 5V line, and in at least one case (the
Asus A7M266-D), both the 5V and the 12V. However, if there's a "P4"
connector on the board, then it's usually a pretty good indicator that the
CPU regulators are hanging off the 12V rail.

[...]
--
Michael Brown
www.emboss.co.nz : OOS/RSI software and more
Add michael@ to emboss.co.nz - My inbox is always open