Power Supply

P

Paul

Hi,

I am building a Pentium 4 based system, but am not sure what wattage power
supply I will require for this. I currently have a 300 watt power supply is
this enough??

Any help would be greatly appreciated.

Cheers
 
J

Jon Danniken

Paul said:
Hi,

I am building a Pentium 4 based system, but am not sure what wattage power
supply I will require for this. I currently have a 300 watt power supply is
this enough??

Without more information, all I can say is probably not.

Jon
 
S

Sooky Grumper

Paul said:
Hi,

I am building a Pentium 4 based system, but am not sure what wattage power
supply I will require for this. I currently have a 300 watt power supply is
this enough??

Any help would be greatly appreciated.

Cheers

Does it have the 4 pin P4 plug?
 
C

Clint Neufeld

Well, I ran my P4 (2.4GHz, overclocked to 3.06) system for awhile (like a
week or two) on a 250W PSU. I had 2 hard drives (one 7200rpm 40GB, one
5400rpm 80GB), 1 CD burner, no extra fans (just the CPU fan), and an ATI
All-In-Wonder Radeon card. I don't think there were any other PCI cards, as
I was using the on-board sound and NIC.

It worked fine, but I didn't want to push it by hooking up my extra DVD
drive, so I ended up picking up a new PSU. So I'd say go ahead and try it,
but leave some budget for replacing your PSU just in case.

Clint
 
C

Clint Neufeld

Good point. My 250W PSU mentioned below (in my original reply) didn't have
the right P4 plug, but my ASUS MB had a special plug that would take a HD
power cable.

Clint
 
S

Sooky Grumper

Clint said:
Good point. My 250W PSU mentioned below (in my original reply) didn't have
the right P4 plug, but my ASUS MB had a special plug that would take a HD
power cable.

Clint

IIRC that 4 pring P4 plug adds extra oomph from the 12V rail of the PSU
to run the CPU, so an old cheapie might not be able to cope even with a
molex adapter.
 
P

Paul

Yes it does have a 4 pin P4 plug, it is a new PSU that came with the case
that I have just brought ... will this make a difference ??
 
W

w_tom

300 watts is more than enough for most any desktop system.
However not all 300 watt supplies are 300 watts. Further
problems are demonstrated by this website:
http://firingsquad.gamers.com/guides/power/default.asp

Look at systems designed by engineers. Many are below or
just above 200 watts. But then those 200 watt supplies truly
can provide 200 watts. Notice the problem cited by Tom's
hardware:

http://www6.tomshardware.com/howto/02q4/021021/powersupplies-15.html
Time and time again, our lab measurements were unable to
verify the output figures represented on the model
identification sticker. And how, exactly, is a computer
purchaser supposed to check the output of a power supply?

Really quite simple to identify a supply that cannot provide
the load. Install the 300 watt supply and run multiple
programs that execute all peripherals simultaneously. Using a
3.5 digit multimeter, critical voltages (3.3, 5 & 12 on
orange, yellow, and red wires) are monitored. If not large
enough, then when supply approaches its upper limit, voltages
suddenly start to drop. Not enough to cause problems, but
enough that it is clear: the last peripheral starting up has
taken power supply to its upper limit as indicated by a sudden
increase in voltage loss.

A simple test, done in minutes, that can answer your
questions since product labels cannot be trusted.

Most common among clone builders is the use of power
supplies that are even missing essential functions - common
among supplies sell for less than $40. 'Self destructive'
supplies are demonstrated in that above Tom's Hardware site.
All outputs for any acceptable supply can even be shorted -
and still no damaged. But in Tom's, some supplies were even
damaged by a less than maximum load!

Many supplies are that inferior as to self destruct. Many
clone builders use the 'we don't need to know' solution called
"More Power". Instead recommend 400 and 500 watt power
supplies rather than fixing the problem: a defective vendor
who sell product only on one specification - price.

300 watts should be more than enough *IF* supply is from a
responsible vendor. Responsible means he also provided a long
list of numerical specifications because essential functions
were inside the supply. If not sure, then simply perform the
above 3.5 digit multimeter test. Learn yourself if supply is
sufficient. Properly sized power supplies go to 100% load
without a sudden voltage decrease.

BTW, why the voltage drop? Because if too much power is
demanded, then the power supply goes into current limiting - a
self protection function. Another reason why supply outputs
can be completely shorted and supply is not damaged - as was a
defacto standard even 30 years ago and require by Intel
specs.
 
W

w_tom

Processors can make sudden demands for power - from a few
amps to tens of amps. Wire and copper traces are electronic
components. Sudden demand changes make those electronic
components apparent. To eliminate adverse effects, the power
supply also connects directly to the processor - the four
prong plug. That connector's job is to eliminate voltage
problems on motherboard that might occur when the processor
suddenly changes demand for power. IOW its job is to reduce
processor induced noise on motherboard. Installed for
reliability reasons.
 
D

David Wright

There are pages out there that rate consumption of various parts and cpu etc.

I rated mine to 276 watts: it was a P4 2.8 gig I think. Onboard sound and vga
would reduce that number. So I think I am going to shoot for a good 350. But
as the other poster says, you could probably do it with an excellent 300.

(e-mail address removed) (Paul) wrote in <9txUb.48347$OA3.15162494@newsfep2-
win.server.ntli.net>:
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top