BigGov

The system specs I will have after my next upgrade of two hard drives, another stick of RAM, two fans and a floppy would be:

Mobo: NF7-S
Processor: Athlon 2500+
RAM: 1 GB PC-2700 Corsair XMS
Video Card: Sapphire Radeon 9800 Pro
Fans: 4 80mm Antec fans
Hard Drives: 1 - 160 GB Maxtor 7200 RPM & 2 - Seagate 80 GB SATA 7200 RPM (run in a RAID 0 config)
1 - DVD-ROM Drive
1 - CD-RW Drive
1 - Floppy Drive

I only have a 400 Watt PS right now and I'm a little worried that this might be a little too much for it.

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One day an Englishman, a Scotsman, and an Irishman walked into a pub together. They each bought a pint of Guinness. Just as they were about to enjoy their creamy beverage, three flies landed in each of their pints. The Englishman pushed his beer away in disgust. The Scotsman fished the fly out of his beer and continued drinking it, as if nothing had happened. The Irishman, too, picked the fly out of his drink but then held it out over the beer and yelled "SPIT IT OUT, SPIT IT OUT, YOU BASTARD!"

Lasereth

It's not the wattage of your PSU that matters the most, it's the brand. A 400w should get the job done if you have a quality PSU, but RAIDMAX and POWMAX PSU's might have issues with it, even if they're 400w.

What kind of PSU do you have?

-Lasereth

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"A Darwinian attacks his theory, seeking to find flaws. An ID believer defends his theory, seeking to conceal flaws." -Roger Ebert

BigGov

Antec, came with the very nice big case

*Wonders how he could leave out the kind of PSU when he said who made damn near everything else*

BTW Las, have you gotten all the soda off yet?

__________________
One day an Englishman, a Scotsman, and an Irishman walked into a pub together. They each bought a pint of Guinness. Just as they were about to enjoy their creamy beverage, three flies landed in each of their pints. The Englishman pushed his beer away in disgust. The Scotsman fished the fly out of his beer and continued drinking it, as if nothing had happened. The Irishman, too, picked the fly out of his drink but then held it out over the beer and yelled "SPIT IT OUT, SPIT IT OUT, YOU BASTARD!"

yakimushi

With an Antec you'll probably be fine.

If not, you'll get random resets or you'll burn it up faster.

Lasereth

The Antec PSU will probably be fine. The worst thing that can happen is your PC not turn on, in which you'll need to buy a new PSU. I've never heard bad things about Antec PSUs, so I assume it'll do fine.

And yeah, I got the Diet Pepsi off.

-Lasereth

__________________
"A Darwinian attacks his theory, seeking to find flaws. An ID believer defends his theory, seeking to conceal flaws." -Roger Ebert

Kllr Wolf

Through my experince that should be plenty. Of course if you add stuff like several lights you might need to increase it.

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Scorpion23

A rule of thumb I've found is that HDs take 25W, as do CD/DVD drives. Motherboards average 100W, and the video card depends on the model. For overkill lets just say 50W for the 9800 Pro, since it requires it's own power connector. 80mm fans also average around 5W, but can vary on the brand and speed.

So based on what you said:
100+3*25+50+4*5+2*25 = 295W

Now we add 50W just as a precaution and you get 345W

Now this isn't counting any additional cards you might have, and overclocking pulls more power than normal. This is also a very general rule, it can vary alot between brands and models. The main thing is what people have said already, watch the brand of PSU you get and you should be fine. Bottom line is a 400W PSU will be fine.

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"Empirically observed covariation is a necessary but not sufficient condition for causality" - Edward Tufte

Wyodiver33

My current system:
Asus A7N8X Dlx Ver 2.0, Uber 1007 BIOS
2X 512MB PC4000 Kingson HyperX, Dual Chan
1X 80 GB WD HDD (8MB Cache)
1X 15 GB Maxtor HDD
1X MSI 52X CDRW
1X Liteon DVD ROM
1X SB Audigy 1
Radeon 9500 Pro
2X 120mm fans, 2X 80mm fans
Thermaltake Xaser III HSF
etc....

So, using using Scorpion23's rule of thumb, which I am not agruing with, my rig should be using at least 270W. Add the 50W as overhead, takes it to 320W. Up until recently, everything was powered by a Sparkle Power Int'l 300W PS with 12A on +12V rail. Everything ran fine, even with the CPU and Vid card OC'd. I guess I got lucky. But just for the hell of it, I replaced that PS recently with a Thermaltake Xaser Silent Purepower 480W PS. It's actually the first PS that I have bought separate from a case purchase. Lol.

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Scorpion23

Wyodiver33, I've got a couple of Purepowers and they've all worked great.

One point I forgot to mention is that you're not going to be pulling full power all the time. Unless you burn a CD, play heavy 3D games and transfer large files all at the same time you're not going to stress the PSU to anywhere near its limit.

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"Empirically observed covariation is a necessary but not sufficient condition for causality" - Edward Tufte

Kaos

I've only heard good things about Antec's PSUs. That should be more than good enough for what you have.

yakimushi

Heh, I had a system that would reset when I put a CD in. Spinning up the CDROM pulled too much power. It was pretty obvious it was time to upgrade at that point

Dragonlich

Just take a look at the +12V info: generally, you want more than about 12 Watts there, preferably more than 16. A really good PSU will give you over 20. I'm running a fully loaded P4 on a 360 Watt PSU (Chieftec), with some 17 Watts on the 12V line, which is plenty.