Hello, first and before anyone make bold accusations ( :shake: ) I did a search on this forum section and I couldn't find anything in something like 50 threads.

I was wondering what would happen if I used a secondary PSU to power up parts of my system like the fans, waterpump, cathode lights? Is it safe for the secondary PSU to just have a load on the 12v and 5v (4 pin molex connector) rails, while the rest are not used? I am not sure but I think a PSU can't operate under these conditions for long... right?

Has anyone made this type of setup? Its just that my Enermax 600w might not be enough for powering up the SLI in my signature and overclock it to the max with 8 high output fans and a 2 amps waterpump. I just want to have an alternative just in case.

Your Envermax 600W will handle those just fine IMO. Some people will chime in a say *gasp*, *gasp* with all that you'll need three PSU's.

Pick up a $30 Kill-o-Watt from your local Radioshack. Use it to determine the total watts going into the PSU. Your system uses about 80% of this.

EDIT: Just to clarify statement above, let's use an example. If the Kill-O-Watt says that your PSU is drawing 200 watts then what's happening is your MB/CPU/Accessories/Etc. are drawing 160 watts and the other 40 watts is being wasted to heat by the PSU. If you wanted to assume the worst case that all of this were going to your 12V line (where most of it goes) then you could figure that that you're now using 160 watts of the 450 (or whatever) your 12V line is rated for.

My guess is that you'll see the meter registering a draw of around 350 watts, maybe 400 watts. And though the meter can't tell you how much of that is being used on the 5V, 3.3V, 12V lines, you'll see the you're so far enough below ratings that you're fine. Again, maybe even assume (for fun) that all of it were going to the 12V line and you'll see that it's fine.

Sounds like an exelent idea to me as the pump is on the 12 volt line and so is just about everything else. I am looking into this my self at the moment.

Que Contrariedad!!!! hehe, nice nick

Nice explanation, I somehow knew my powersupply was beyond the power needs of my system... yet if something failed with a tinny overclock I right then looked at the Enermax as the culcript; hehe, as if the other stuff was inocent.

I will have the second PSU option opened, I wish to know if using only 5 and 12v outputs on this one would be safe or if I need to connect its ATX connector. Also the Kill-O-Watt thing, hmm sounds interesting since I didn't knew they had something like that... hmm, looking at their site (www.radioshack.com) I can't find it; do you have a link? I have to get one of these things

I am moving my system into a Cooler Master Stacker case (the first model) because of the space, ventilation, and because it has space for a second psu just in case. Still with all that space, the radiator is staying OUT!

I didn't see it on RadioShack's website either. Maybe someone can. Here's some other random store selling it.

http://www.supermediastore.com/kilwateldet...awatt&WT.srch=1

In terms of your original question... At my office we have a file server with something like 18 SATA hard drives. There are RAID controllers in the file server with 36" SATA cables going out of the server chassis into external enclosures (each enclosure holds 4 SATA drives). Rather than relying on the server's PSU to power itself and all the drives, we have one PSU just sitting on the rack hooked up to all the enclosures. To accomplish this we just jumpered the green + a black (google this if you're not familiar). The setup has been running for months now without any problems.

Curious about the draw on that external PSU? Each SATA drive draws about 10 watts though they draw more on startup (which is why it's nice that the RAID controller assists with staggered startups).

It's amazing and cool what a world-wide following DFI has. Viva Mexico (yo vivi en la Argentina por dos anos).

Really? What was your favorite Fútbol (soccer) team over there in Argentina????

The only thing I am worried about is if the PSU needs to have a load on every rail, because if the ATX connector is just sitting there unhooked thats what is going to be. SATA HDD's use 12 and 5 volts, I think, the same with fans, and the waterpump.... but what happens to the 3.3 volt line? If that external PSU you have on that server is working fine with only 12 and 5 volts being used it is great news.

Yep, I need to Google this and spend some time on it.

Man, I need one of those Kill-O-Watt things!!!! Its a dream come true, how many times I needed something like this in the past.

Yep, you were right Contrariedad... there is no real danger, or any I have found so far, with a power supply just using the 12v and 5v outputs; actually using the 5v a little is enough to keep the power supply working with out problems.

I found this article at the place I least expected to find it (www.frozencpu.com btw):

http://www.virtual-hideout.net/guides/atx_...ods/index.shtml

This is the way I would like my setup to be if I ever need a second power supply: a switch to manually turn on fans and waterpump. With the second psu I might be able to use more powerful Delta or Vantec fans to cool down the radiator, using a fan controller of course (and watching how many watts it can control). Also if I shut down the system this manual switch will let me keep the cooling running for a while if I choose to; I doubt I will ever forget to turn it on, since the cathode lights would be powered up this way too.

Smoken Joe, the only real problem about using a second power supply is space... the Cooler Master Stacker case has everything, even the ATX connector to do the job (switchless), but its for 20 to 20 pin ATX connectors. I like the manual switch better. Only thing the Stacker doesn't have, so far, is a side panel with a window in black color; found a couple of stores which have them, but they are either expensive or just not NewEgg.com

Now the only thing is to find a really cheap psu to do this job... yet not cheap enough to fail just powering fans, waterpump and lights; cheap psu's do this btw :shake:

I use a External PSU 480W without any problems :nod:

Works very good, I have 9 fans with it.. :nod:

You'll kill me but I have to admit I wasn't a huge Fútbol fan. Nonetheless, you can't live in Central / South America without being fan of some team so I chose Boca! Those were back in the days when Maradona (was that his name?) was still playing.



Yeah, it works fine for us at the office!

NOOOOOOOOOOO!!!!!!

Hehe, well its easy to follow one of the gzillion teams in Buenos Aires... specially if you lived there. Boca is a nice team, and Maradona was one of the top 3 players of all times (regardless of what some people say)... yet that team I don't like much, specially since recent days; their fans are just terrible.

I would have prefered River Plate instead... but I would probably be fan of a smaller team. I am already a fan of a soccer team here in Mexico, and not even with all the money in the world would I change it; of course I would accept the money and say "hurray for X team"... but deep down I would be thinking "yeah right :shake: "



Well I am going to use a secondary PSU once I have my new case here, there is no point in not using one if it has the space. Right now I have 14 fans in the case, including PSU, and the new one will have 5 less. Aparently the power quality has something to do with overclocking, specially the video cards... too much load on the system and the power isn't clean enough, so overclocking is not going to be much... I hope the second psu will solve this.

Sounds great, let us know how it goes! And you're exactly the type of adament soccer fan I've come to expect from Mexico down to the tip of South America!

I have no problem powering one of my rigs with the Enermax 600W SLI ready PSU

NF4 SLI-DR
FX-57 San Diego
3x74GB Raptors Raid 0
2x512 plat rev.2
2xEvga 7800GTX
Enermax 600W SLI ready.
DD watercooled
10x120MM fans(6 on BIX III)
6x80mm fans
DVD rom
floppy

The line is very stable.

How many fans do you have on your system Oliver? I have 14 (minus the ones inside the Enermax)... but changing into just 8 in the new case.

Also the two 6800GT's need more power than two 7800GTX's, same as with four Hitachi SATA II HDD's vs. two Raptors.

I believe the diference betwen our systems is small, and yes the Enermax does the job right now... but I think it might be better to unload it a little so the voltages on the video cards are cleaner, same with the CPU. Besides, its so easy to have a second psu... :cool: