Shared Knowledge
“How to: Select a PC Power Supply
(Watts)”
Summary: A PC power supply can be had for as little as $20 or it can cost as much as almost $1000. What? Why not just buy the $20???
Suspect most folks do not
even know what size (in watts) power supply they have in their personal
computers (PC) and what does it matter if their PC works? Well, for sure, some
PC users never upgrade their hard drives or add additional hard drives or DVD
or CD burners, or memory or faster video cards, but some of us do.
Been into plenty of PC’s over
the years and amazing what I find. Don’t understand or actually I do, why a
manufacturer would put a 90 watt power supply in a PC or a 200 watt. While
these may work for the configuration they are selling, these size power
supplies just won’t cut it if the user adds to or changes much of anything.
Now in my case, I build my
systems from scratch and my main machine uses an Intel motherboard, 3GHZ
processor and I have 2GB of PC3200 memory, 2 hard drives, a CD burner and a DVD
burner and 3 case fans besides the fan on the power supply and the fan sitting
right on the CPU chip. When I built my system, I knew I was going to need a
supply which provided an extra 12 volt connection to the motherboard and also
one, which had a thermostatically controlled cooling fan. So, given all this
and not into actually calculating loads for the various voltages supplied by the
power supply, I settled on a top of the line, 465watt.
Since building my main
system, all has been well. I have had no problems related to power or I didn’t
until I tried to add a new 500GB SATA drive tonight. At first it appeared that
the power supply could handle my entire load but then a sudden system shutdown
and restart and then another. So unhooked the SATA drive and booted again.
After the scandisk operation and then another one right after that, the system
is now stable again but obvious that I need to upgrade my power supply from my
current 465.
500? 600? 750? 1000? From
researching, it would appear the world is awash in PC power supplies and like
just about everything, it is hard to be able to get a decent comparison between
any 2 in terms of amps supplied at various voltages.
Recently, I worked on a Dell
8200, which was made in 2000. Although had not planned on it, wound up
replacing hard drive, memory, video card and CD burner and after finding out
that the system only had a 200watt power supply in it, upgraded that too to a
600watt model. No problems with that unit now but was disgusted that Dell saw
fit to not have a master switch on their power supplies and thus any off the
shelf supply would not fit because there was no place in the case for the
master power switch, which is standard on any off the shelf supply today. Well,
could have paid Dell or one of the third party supplies a fortune for a supply
that would have just dropped into place but I just could not do that and so I
cut out a chunk of the back case to accommodate an off the shelf supply with
master switch. What would it have cost Dell to have put a master switch in
their power supplies? Another dollar or 2?
Back to my system. As I have
on order a new video card with 512MB of Ram on it and I already know that my
465 won’t cut the add of another drive, just going to go with a 750watt.
Probably more than I need but who knows what I might do tomorrow. Still have a
connector for another SATA drive and space in my full tower case.
Guess the bottom line here is, if you are thinking of adding more drives or upgrading your video card or adding more memory, you better take a look at the size of your power supply as you might have to upgrade that as well. And given my experience tonight, if you upgrade some components and the system starts becoming unstable on you, don’t forget that it could be the power supply crapping out on you.