Tech Support > Computers & Technology > how big should my power supply be?
how big should my power supply be?
Posted by tempus fugit on February 22nd, 2004


Hey all;

My computer has been acting weird lately (random reboots, random shutdowns,
reliablity issues, etc), and I'm starting to wonder of my PS is on it's way
south.

I'm currently using a 300W PS (don't remember the brand), on my Windows 98SE
with Athlon 950, ECS K7S5A mobo, 384 megs PC133 RAM, DVD rom, CDRW, 2
soundcards, ATI 128 Meg video, and 2 hard drives (1 is 5400 RPM, the other
7200). I think that covers it. Can anyone advise me or point me to a site
that outlines the typical current requirements of these devices so I can
figure out if I should go to a bigger power supply?

Thanks



Posted by Drifter on February 22nd, 2004


On Sat, 21 Feb 2004 22:07:07 -0500, "tempus fugit"
<toccata@ciaccess.com> wrote:

Well, you don't give a lot of specifics to work with but some general
rule-of-thumb guidelines...

O/S doesn't matter in this case.
Athlon 950 -up to 50 watts
ECS K7S5A- 20-30 watts
384 MB RAM 20-30 watts
DVD ROM- 20-25 watts
CD-RW- 20-25 watts
Sound card 7-10 watts (you say you have 2 so 14-20 watts)
Hard Drive(s) 15 watts (x2- 30 watts)
Video card Hard to guess without the specific model, but we'll
say 30-50 watts.

So running on the higher estimate you need roughly 260 watts. Now add
in roughly 10% to cover the internal loss when the power supply and
computer warm up and you are at about 286 watts.

In addition it has become widely known that far too many brands of
power supply provide as much as 15% less power than their sticker
"rating" claims (that could put your power supply down as low as 255
watts).

So in summary, yes I would say you probably need a larger power supply
(say 350-400 watt). Make sure you buy one with a solid reputation
like the Antec "True Power" series. Do the research BEFORE you waste
your money.


Drifter
"I've been here, I've been there..."

Posted by DeMoN LaG on February 22nd, 2004


Drifter <zespectre@askme.com> wrote in
news:bgcg30ddkdktrhv2e7eq2qap2p8dr036um@4ax.com:

Complete crap. I've run a Duron 1.2 with 2 IDE drives (5400 and 7200 RPM),
an IDE RAID controller, a SCSI controller, 2 5400 RPM SCSI drives, and 512
megs of RAM on a 300w supply with no issues at all. The main question is
the quality of the drive. Get a high quality Antec or Enermax, or Sparkle
power supply, and you can get by with a lower rating. If you buy a cheap
$15 power supply, then you'll get crap output.

--
AIM: FrznFoodClerk
email: de_on-lag@co_cast.net (_ = m)
website: under construction
Need a technician in the south Jersey area?
email/IM for rates/services

Posted by Thor on February 22nd, 2004



"DeMoN LaG" <n@a> wrote in message
news:Xns9497170119DFCWobbly@208.42.66.156...
2 optical drives (both burners)
80GB 7200 HDD
512MB RAM
Athlon 2100+ T-Bred
extra USB 2.0 card w/5 ports
sound
modem
NIC
A7N8X Mobo
Geforce 4 Ti 4800
5 case fans
all on a PC Power & Cooling turbo 350 power supply. And it barely gets warm.






Posted by Drifter on February 22nd, 2004


On 22 Feb 2004 07:15:59 GMT, DeMoN LaG <n@a> wrote:

DeMoN:
You post here a lot and you give a lot of advice, but jeez can you
dump the damn attitude you've picked up lately. You can say you
disagree with me without being a jerk about it.


Drifter
"I've been here, I've been there..."

Posted by Michael-NC on February 22nd, 2004



"Thor" <man@arms.com> wrote in message
news:103hdr4rtg5le35@corp.supernews.com...

Athlon 1GHz, 512MB ram, 2- 7200 HDDs, 52X Burner, NIC, Cordless Mouse/KB,
8MB Intel I740 Video on a 250 Watt PS from QuietPC.com. The units been
running trouble free, 24/7 for well over a year. Quality counts.







Posted by Drifter on February 22nd, 2004


On Sun, 22 Feb 2004 09:09:32 -0500, "Thor" <man@arms.com> wrote:

Numbers guys, numbers.
Abit BH7 Mobo (Incl NIC and Audio card): 50 watts
Intel P4 2.4b CPU: 75 watts
1gb RAM 30 Watts
ATI Radeon 9700 Pro Vid Card: 30 watts
4 IDE HDD (15ea X 4) 45 watts
IDE RAID card 07 watts
Hercules Sound card 09 watts
CD-ROM drive 25 watts
DVD-RW Drive 25 watts
FDD 05 watts
Vid Capture Card: 15 watts
Case Fans (4 each X4) 16 watts
Vantec Tornado Fan 09 watts

Total: 341 watts

Now according to the numbers I obtained -from the manufacturers- I
should have been able to run my system with a 350 watt power supply.
Guess what, didn't work even with a TruePower supply. Found out later
that the Vid Card was actually pulling about 45 watts and the RAM was
pulling about 40 watts for a total of 366 watts. Had to jump up to a
400 watt before everything settled down and played nice.

My point is that the numbers I gave the OP were an estimate based on
his somewhat sketchy information (very few model numbers, etc) and
based on that estimate he could be running close to, or over, the wire
ESPECIALLY if he has a cheap power supply.


Drifter
"I've been here, I've been there..."

Posted by Travis Nowicki on February 22nd, 2004


Dear: Tempus,
I don't think your Power supley is not powerful enough, I am using WIndows 98SE
two and know that the operating system can not handel A DVD ROM and 384 PC RAM.
It could handel a CD-RW, but not a DVD-ROM(DVD-ROM's need a lot of power and
speed:-).Two hardrives might be a little hard to process(Even know it donsen't
show) Harddrives on Windows 98SE must be under 20Ghz.If your computer is
processing under 1.5Ghz it would be good to Take the DVD-ROM out of the
computer.It is possable that your PC could not give enough power, but that's
preedy rare.

tempus fugit wrote:


Posted by Wizard on February 22nd, 2004


I gave him the same friendly advice 6 months ago and he didn't take it
so I just kill filed him and have not missed anything significant that I
can tell.

Drifter wrote:

Posted by DeMoN LaG on February 22nd, 2004


Travis Nowicki <trav1085@emailaccount.com> wrote in
news:4038AA6B.74F8EA9B@emailaccount.com:

.... I am really not certain where to start debunking this. 9x can easily
handle a DVD, multiple hard drives (really you could have 15 hard drives
and 9x won't care), and Windows 9x can run with up to 1 GB of RAM with the
right little trick, otherwise the max is 512. It is not at all rare for a
PC to not get enough power. I had a customer just last week who bought a
custom system with an Athlon, DVD, CDRW, 2 HDDs, extra NIC, sound, and a
GF4 for video that used a really cheap (I'd put it in the $10 ballpark)
power supply. Sure, it was 400w, but the voltages coming off of it were:
3.3: 2.9
5: 5.6
12: 12.89
VCore: 1.85 (at the lowest possible setting in the BIOS of 1.65)

Machine crashed, locked up, worked like poop. Replaced it with an Antec
400w unit, voltages came back to spec, machine worked like a charm.

--
AIM: FrznFoodClerk
email: de_on-lag@co_cast.net (_ = m)
website: under construction
Need a technician in the south Jersey area?
email/IM for rates/services

Posted by tempus fugit on February 23rd, 2004


You gave ME friendly advice 6 months ago? I don't think so... at least I
don't remember asking this question (this is the first time I've had
problems like this).
"Wizard" <no@stinking.ads.com> wrote in message
news:4038E97E.761778F8@stinking.ads.com...


Posted by tempus fugit on February 23rd, 2004


I am thinking that I need a new PS at any rate, and figured I might as well
go a little higher if it would help. I'm also having problems with burning
CDs, system lockups, monitor display screwups, etc. that seem to be resolved
for a while after a reboot.

I know it's hard to say for sure with all the different components involved,
but do these things sound like PS problems?

Thanks to all who posted.




"Travis Nowicki" <trav1085@emailaccount.com> wrote in message
news:4038AA6B.74F8EA9B@emailaccount.com...


Posted by Drifter on February 23rd, 2004


On Sun, 22 Feb 2004 20:30:49 -0500, "tempus fugit"
<toccata@ciaccess.com> wrote:

He was referring to DeMoN.


Drifter
"I've been here, I've been there..."

Posted by Michael-NC on February 23rd, 2004



"tempus fugit" <toccata@ciaccess.com> wrote in message
news:9Dc_b.45667$uE1.15374@nntp-post.primus.ca...
It wouldn't hurt to buy a quality 450 watt power supply and swap it out. If
that don't do it, you still have a new, quality 450 watt power supply for
your next upgrade.



Posted by tempus fugit on February 23rd, 2004


Good advice, to be sure. I was kind of thinking along those lines (although
not quite as high as 450)

Thanks


"Michael-NC" <NoAddress@desolate.com> wrote in message
news:IEd_b.36260$jx3.4004440@twister.southeast.rr. com...


Posted by tempus fugit on February 23rd, 2004


My mistake. Sorry.


"Drifter" <zespectre@askme.com> wrote in message
news:vkoi30t5e2p9otb95kdh2kf136rkgm5osm@4ax.com...


Posted by Michael-NC on February 23rd, 2004



"tempus fugit" <toccata@ciaccess.com> wrote in message
news:0Be_b.45871$464.30084@nntp-post.primus.ca...
Only reason I suggest a 450 is to "future proof" the component for another
system.




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