Seasonic S12-330W enough for this spec?

maxxymus · Post by **maxxymus** » Tue Aug 08, 2006 3:52 am

Hi guys,

I am interested in getting myself a storage pc that will consist mainly of:
- 4x WD 320GB KS in RAID 5
- AMD AM2 35W cpu (one of them... a sempron probably)
- 512mb RAM
- Gigabyte/MSI raid5 capable mobo...
- Probably onboard GFX

So I am looking for a silent and safe (for the HD's) solution for a PSU. Will this PSU suffice? Or should I look at the 430W? The PC itself will also be hooked up to a UPS.

Cheers

burebista · Post by **burebista** » Tue Aug 08, 2006 4:20 am

It's more than enough.

Aris · Post by **Aris** » Tue Aug 08, 2006 6:13 am

The general rule of thumb is:

If your using onboard graphics, 200w is enough
If your using a single graphics card, 300w is enough
if your using dual graphics cards, 400w is enough

its not very scientific, and it doesnt work in ever scenerio, but its a good starting point for planning out system power requirments.

maxxymus · Post by **maxxymus** » Tue Aug 08, 2006 6:54 am

thanks for the replies...

more so, if anyone can tip me on whether I should blow the cash on a 35W sempron instead of a 65W and just use Cool'n'Quiet? the cpu will be mostly idle anyway. Or will the difference in wattage even out in the electricity bill in the long run? (the pc will be on 24/7).

Cheers

jaganath · Post by **jaganath** » Tue Aug 08, 2006 8:30 am

if anyone can tip me on whether I should blow the cash on a 35W sempron instead of a 65W and just use Cool'n'Quiet?

From what I can see, the only difference between the 35W and 62W Semprons is the voltage, 35W is 1.2/1.25V, 62W is 1.25/1.4V. If you can find an AM2 mobo that undervolts you can do this yourself.

CPU Comparison page AMD website

vitaminc · Post by **vitaminc** » Tue Aug 08, 2006 10:09 am

You probably need some 300-350W just to be safe, since you are running 4 HDD.

http://www.extreme.outervision.com/psucalculator.jsp

Aris · Post by **Aris** » Tue Aug 08, 2006 10:42 am

vitaminc wrote:You probably need some 300-350W just to be safe, since you are running 4 HDD.

http://www.extreme.outervision.com/psucalculator.jsp

that PSU calculator sucks. Ive seen it posted on this forum before, and all the regulars noticed almost every facet of it is flawed in some way. Most of the wattages it specifies for things are GREATLY exagerated. I think when i put in my system it told me i needed a 450w PSU, when a 300w is still way more than i actualy use.

typical power draw for 3.5" hard drives is around 10watts

4x hard drives would be 40watts

motherboard/cpu even with the 62w sempron would only be about 80watts, even less if he undervolted it or went with the 35w version.

10w for an optical drive

lookin at around 130w, it MIGHT peak at 150w during bootup or strenuous acticity

k2tsai · Post by **k2tsai** » Tue Aug 08, 2006 11:13 am

Hard drives can draw as much as 20w on power up. (Some SCSI drives can draw upwards of 30w). It's one of the reasons that SCSI allowed for delayed spin up so that you didn't have upwards of 10-14 drives all trying to spin up at the same time and blowing the power supply.

Also factor in ~80% efficiency on the power conversion (S12 should be higher than 80%, but let's be conservative).

That said, while I think Aris' 130-150w estimate is low for power-on draw, I do agree with his estimate that the S12-330 should be sufficient.

vitaminc · Post by **vitaminc** » Tue Aug 08, 2006 1:50 pm

Aris wrote:
vitaminc wrote:You probably need some 300-350W just to be safe, since you are running 4 HDD.

http://www.extreme.outervision.com/psucalculator.jsp
that PSU calculator sucks. Ive seen it posted on this forum before, and all the regulars noticed almost every facet of it is flawed in some way. Most of the wattages it specifies for things are GREATLY exagerated. I think when i put in my system it told me i needed a 450w PSU, when a 300w is still way more than i actualy use.

typical power draw for 3.5" hard drives is around 10watts

4x hard drives would be 40watts

motherboard/cpu even with the 62w sempron would only be about 80watts, even less if he undervolted it or went with the 35w version.

10w for an optical drive

lookin at around 130w, it MIGHT peak at 150w during bootup or strenuous acticity

Well, that calculator is by no means 100% perfect, but its a start.

3.5" HDD draws different amount of current depending on the spin speed.

My Cheetah 15k RPM Ultra 3 SCSI HDD probably draw twice or 3x the power that a normal 7200RPM HDD does.