Multiple Mobo's sharing a single PS

[Mandrill]

I saw Lord D's Rifter page and I was wanting the scoop on how many mobo's canbe supported with one PS and what that wattage would be? I have parts left over that I could turn into a crack rack and I am looking for some guidence.

 

[Train]

im sure its possible, as long as they dont suck too much power, i wouldnt do it, unless i really needed to right then and there. Power supplies are cheap enough, just go get a cheap used one for like $15 or less

 

[Lord Demios]

I would use the rule that each board you use will pull 60 watts. I know some board pull less then this (pentiums) and some quite a bite less than this (P-2's/Celerons) but that is what to figure it at. Plus you don't want to run each power supply at FULL power.

Any more questions feel free to ask.

LD

PS, if you have a watt meter, you can customize it quite a bit more. That is how I came up with that rule. I measured many machines running at FULL cpu, and then found out howmuch a Power supply can really give. Moding power supplies TAKES TIME. It's not a quick process, and if you make a mistake, it will cost ya. SO test the power supply with a multi-meter before you try it on motherboards.

Good Luck

 

[BoberFett]

Here's a wacky question. How would this even be possible? How do you physically hook multiple motherboards to a single PS? Do you make a mod to the ATX power connector?

 

[denali]

It might just be easier to get some cheap power supplies. I had cautrey send me a case of I thnk 8 145W power supplies for like $8 each. By the time you get all the parts and do the work the cheap power supplies won't cost much more, although they would take up more space.

 

[Mandrill]

The reason I want multiple mobo's per PS is to save electricity. One PS eats less power than 3 One PS takes up less space than three. One PS is cheaper than 3. :0 I am a cheap person. I'm willing to spend the time to save the money.

As far as modding the PS goes. What else has to be done aside from just splicing on more mobo power connectors? Is there more to it than that?

 

[Kwatt]

Mandrill

Here's what I did.
Ext. cables here:
AT http://www.jameco.com/cfm/viewdesc.cfm?part_num=130809
ATX http://www.jameco.com/cfm/viewdesc.cfm?part_num=170237
I got to this place from a link on LD's site. Thanks LD
Their shipping is resonable and fairly quick.

Then I got dead PS's from my junk pile and local Computer stores.
And cut the MB connector's off with as much cable as I could.
Then got some running taps 3M part #558 for wire size 16-22. You can get these at an electrical supply house. You may have to order them cost apx $15 per 100.(a company called GB makes something similar but I don't think they are as good the plastic on the GB's mashes) Use these to tap the tail onto the ext. cables. I like this because I don't have to mod the PS's. Then plug in as many tapped ext. cables as you need based on the # of MB's your PS can power. However these taps are only rated for a couple of amps so I'm not going to run more than 2 MB's off one PS. I don't want to burn up a MB trying to save the cost of a PS. I'm only mounting 2 MB's on a shelf anyway.

I have only tried this on an AT PS so far. The place I got the taps only had 20. I'll have to order a full box before I can try it on an ATX. Maybe In a week or so I'll be able to let you know.

Kwatt

 

[jatwell]

Here, you might save a couple bucks on the extensions:

http://www.pccablesdirect.com/main/Power.htm

ATX for $4
AT for $3

 

[cory]

you can get brand new atx p/s for about $11
i got 14 of them from one place for my cluster.

the amount of power that is wasted in the p/s is not going to
be that much. my guess is that the power waste by one p/s
would be under a watt. compared to the power
use of the mb itself it is a very tiny fraction and would
only amount to a couple of pennies a month.
the atx p/s that i got have a fan speed that depends on how hot
the p/s is so it hardly spins when it is just powering
the mb(it would make more sense if you wanted to save elec
to just take the fan out of the ps on a ps that doesnt have a
speed adjust fan)

and with atx p/s it isnt worth the hassle
cause an atx p/s is turned turned on by the
mb thru the power connector so you would have
to isolate the some of the wires and come up with
some way to turn the p/s on
(not like an at p/s that has a real switch).

i had thought of puuting more than one mb per p/s but when you
figure all the wasted time and having to turn the machines
on together i opted for the seperate p/s

 

[networkman]

denali,

Could you post a URL or Email for where you got the 145 watt power supplies? I'm thinking of doing the crackrack thing too, and compared to using 230watt P/S's, it's alot of power saved across a dozen machines at home.

Thanks.

 

[cory]

you know that a 145 watt ps is not going to use more power than
a 250 watt if the load is the same.

those are the maximum ratings for the ps not the amount
of power that it will consume at all times.

the power that is uses depends on the load.

ie if you had a computer connected to a ups and did not have the
hard drives running or the processor and other things at idle
it would run much longer on the ups.