Power supply question...

[NLS]

Continuing my quest to build this thing with minimum components to buy, I have to think of the PSU.

 

I have two spare PSU.

 

One is 500W but only has four MOLEX connectors (2x2 cables).

+3.3V  28A

+5VSB 2A

+5V    35A

-5V    0.3A

+12V  20A

-12V  0.8A

 

The other is more complete (and V2.2) but with much less power: 350W.

 

+3.3V  28A

+5VSB 3A

+5V    28A

+12V1 10A

+12V2 15A

-12V    0.8A

 

...the thing is that this second PSU, has 5 MOLEX and 2 SATA connectors!

 

I will probably connect (initially) 4 IDE and 2 SATA disks (and all future disks will be SATA as I've mentioned in other threads)... the mobo will be used with a P4 (478) @3.2GHz and an oldie 6600 VGA (which I remember though, needs a MOLEX for itself!)

 

We are at time of HUGE PSUs (my gaming machine has a 1KW PSU), but how much will REALLY be enough for my rig? Will I get by with the 350?

 

Also (bonus question), how safe will be to use MOLEX and SATA power splitters?

 

 

[goofygrin]

The problem you'll have with the second psu is that it has split 12v rails.  So the drives will be limited to the 15A.  On the 1st PSU, the MB and drives will all share the 20V.  Keep that in mind.

 

I think you're way overkill on the CPU (that CPU uses a ton of power/heat) and video card (holy crap batman, this box will run headless... if you could get away with it, you'd not even need a video card).

 

I've got 6 iTB drives in a box with a 400W PSU and it's working fine.  One more drive though and it causes one of the drives to not spin up.

 

In my old server with 12 drives, I ran dual PSUs with an ATX power splitter (I made it with a couple ATX extensions, about $15 in parts from Fry's).  It was really loud though (one of the reasons I decommissioned it).

 

I've used power splitters and they are A-OK.  I actually like using molex connectors since I don't have to rely on friction to hold the power cable on (these 1TB drives I've got spin like a mofo).

[NLS]

Hm so maybe none of the two is ok for me... right? One is too low total and the other is too low amps on 12V...

 

My case doesn't fit both PSU.

 

As for the CPU and VGA... I just have those. If the VGA would be a problem though, I am sure I can find in my closet some much stupider VGA AGP card.

I am keeping the CPU though, as I would only replace it with something less, if there was one of MY machines with worse CPU (I am not going to upgrade someone else's CPU because I don't need 3.2)... of course it is always possible to downclock it. It is an Asus mobo after all.

 

I'll see...

 

Thanks.

[goofygrin]

I personally would try them both.  If they boot and seem stable with all the drives then you're ok.  I think you'll likely have more success with the older one.

 

And if you can find some old junky agp card, that'd work well.  Less pull on the 12v and 5v rail since it won't be using so much juice.  If there's a local version of craigslist there, you might try.  I can buy cheap AGP video cards for about $5 all day long here (heck, I've got two sitting on my desk right now).

[NLS]

I most probably already have.

 

We'll see.

[BLKMGK]

I personally would try them both.  If they boot and seem stable with all the drives then you're ok.  I think you'll likely have more success with the older one.

 

And if you can find some old junky agp card, that'd work well.  Less pull on the 12v and 5v rail since it won't be using so much juice.  If there's a local version of craigslist there, you might try.  I can buy cheap AGP video cards for about $5 all day long here (heck, I've got two sitting on my desk right now).

 

Agree, these days of bigger is better people tend to go for HUGE power supplies when in reality they do not need quite so much. I too have dual P/S in one of my unRAID and thinking about it I believe it's overkill. It's running fine though so I'm not touching it The second NAS has I think a 400 or 450 in it and I do not intend to add a second - it's at 8 drives and climbing. The kill-a-watt says it's not using much juice at all and my SATA cages only use 3 power connectors for 5 drives. I'll use splitters without a second thought and did in my first machine before buying the second P/S. Seasonic and Sparkle are good P/S - look for the 85+ rating if you want to keep power usage way down.