Another "What power supply do I need?" Thread

[vetteguy]

I'm currently overhauling my server, and will need to get a new Power Supply, but even after searching around here I'm still a little unsure. I've seen some threads with supposed "average" power consumption numbers, but some argue that they aren't realistic. Anyway, here's my list of what's going to be in the server, and maybe you can give me your opinions:

AMD Athlon 1.0GHz
Asus A7V Motherboard
2x256MB Crucial PC133 RAM
40X CD-ROM
8MB AGP Video (generic)
10/100 Ethernet Card
Promise SX6000 IDE RAID Controller
6x Western Digital 80GB Special Edition 7200RPM 8MB Cache Hard Drives

I ordered a new Chieftec case to put this stuff in, and it is coming with a 430 watt power supply. Would that be able to handle this stuff? Or would I need to look at a 550? By some of the numbers I've seen, this should be running around 378 watts, so I think it should be ok, but I'm open to suggestions.

 

[bozo1]

Keep in mind that the drives suck a good bit more on the 12V line during spinup. Don't know what that would do to your numbers.

 

[vetteguy]

Thanks for the info...I was looking at your system and I see you use a 550W, of course you have 5 UW SCSI drives which have got to pull more power than the IDE ones. But I guess in the long run it won't hurt me to have the extra wattage (I'd rather do that than not have enough). What are your thoughts on Enermax? I have a 431W in my PC right now, and I haven't had any problems. I don't think they make a 550W though, but Antec does (I believe).

 

[paralazarguer]

If you are trying to determine how much power you will need for your new system read this guide here Everything you've ever wanted to know about power supplies.

 

[bozo1]

I had a 431 Enermax for a number of years and it ran all of my stuff fine. It died recently so I had to buy one locally - the 430 Antec's were out of stock so I went 550. The only reason I went 550 was because it was in stock.

 

[bozo1]

Originally posted by: 7757524
If you are trying to determine how much power you will need for your new system read this guide here Everything you've ever wanted to know about power supplies.

Once again, you post a link that has nothing to do with the topic. We know how powersupplies work. The question was what would be adequate for his particular setup since he is running 6 hard drives which few people do.

 

[vetteguy]

Originally posted by: bozo1

Originally posted by: 7757524
If you are trying to determine how much power you will need for your new system read this guide here Everything you've ever wanted to know about power supplies.

Once again, you post a link that has nothing to do with the topic. We know how powersupplies work. The question was what would be adequate for his particular setup since he is running 6 hard drives which few people do.

Thanks...I thought I was missing something in the link that they gave.

I'm thinking about getting an Enermax EG651P-VE which would give me 551W. I think that a 430 would cover it, but at least this way I know I have room to breathe. Now I'll need to find a buyer for my surplus 430W!

 

[Pariah]

You can run that setup safely on a 250W PS. 300W will give you plenty of breathing room. A 330W Antec TruePower will be more than enough and save you money for other purchases.

 

[paralazarguer]

"The question was what would be adequate for his particular setup since he is running 6 hard drives which few people do."

Yeah, that's why I gave the link. It provides a guide for calculating how much power you will need on each rail for your devices. Read the article before you knock it. If you don't understand then try another guide. The answer to how much power do I need is in there.

 

[vetteguy]

Originally posted by: Pariah
You can run that setup safely on a 250W PS. 300W will give you plenty of breathing room. A 330W Antec TruePower will be more than enough and save you money for other purchases.

I checked out a site that gives average power consumption for components (actually a range). I used the highest estimated number for everything, and I came up with 378W. I guess I could try the 430W that's coming with my case and see what happens.

 

[paralazarguer]

Again, you can't take the power requirements of all devices and add them together to get 371 or whatever. It just doesn't work. You have to make sure that the 12v rail can handle the load of 6 hard drives. Having all that extra power on 3.3+5 isn't going to do you any good if your load comes from 12v devices. This is explained in the article. Make sure that you take that into consideration. Good luck!

 

[Pariah]

"I checked out a site that gives average power consumption for components (actually a range). I used the highest estimated number for everything, and I came up with 378W."

You cannot get an accurate estimate by adding up components like that. There is no easy way to estimate power needs besides looking at what lowest PS someone else is running with a setup similar to yours. I can tell you, I've had 6 hard drives, 1 10k and 1 15k SCSI drives, 3 optical drives, 1.4GHz Athlon with assorted other hardware running on a standard 300W Antec PS in the past without any issues. I've seen people runing SMP Athlon systems on 300W PS's. The current viewpoint that nothing below a 400W PS can run anything but a 386 with a 4200RPM drive and floppy drive is myth that needs to go away.

 

[paralazarguer]

That's correct and is evidenced by the fact that most OEMs ship top of the line systems with 250watt power supplies. You can't figure out how much power you need just by adding the power need of all devices together you have to calculate on a voltage by voltage basis and when you do, unless you have, say, 6 hard drives, you're going to find that all you need is a 200watt power supply. The math can all be found in that article or the article in pcterms.

 

[vetteguy]

I wasn't trying to start a debate here, I just wanted an idea of what kind of PSU to use. Although a 300W may well indeed run this system, I'd rather be safe than sorry. Having a 430W is not going to hurt it, my main question was would the 430W be ENOUGH? Apparently it will be, so I appreciate the comments and suggestions. Once I get everything shipped to me and assembled I'll see if it blows up.

 

[paralazarguer]

You have to focus on that 12v rail. The others aren't important since you won't be stressing them like that one. Even with 6 hard drives, two optical drives, and all 6 PCI slots loaded, I would say that 430 would most definiltey be enough. Good luck.