1040W 2x33A OCZ Power supply ?

[eva2000]

Not really but... with SLI setup would be ideal to have 600W SLI psu with 2x PCI-E connectors, + 3 cables each with 3 sets of molexes = 9 molexes + 1 floppy

when you run additional water cooling gear with thermochill 120.3 with 3x 120mm fans and pump you need the extra molexes.

for now decided to get these adaptors http://www.coolpc.com.au/catalog/product_info.php?products_id=630 so i can run dual psus with my watercooling and additional fans off the 2nd psu and leave free molexes on main psu for my PCI-E cards

would there be any probs running dual psu using the adaptor http://www.coolpc.com.au/catalog/product_info.php?products_id=630

and having 2x 520W OCZ PS and having their adjustable rails at different levels ? i.e. if the 2nd psu only powers my water cooling gear i could overvolt my MCP650 pump to 12-13V while keeping main psu at 12.2V ?

[jinu117]

Err... no load on 5v line I can see nor 3.3v line... if you plan to use it for 12v only... that doesn't sound too safe.

[eva2000]

maybe plug 1 molex from 2nd psu into a harddrive ?

[STEvil]

No problems with using the adaptor, its a good idea actually. Maybe i'll chop up an old dead motherboard and make one myself ;)

The problem this adaptor brings is that powering your video cards with seperate power supplies (or even the same one) can cause leaking voltage and current due to different power outputs.. Thats why some video cards can be powered by a seperate PSU while others will die. Same deal with motherboards.

Also the reason I dislike PSU's with multiple power rails (dual/tripple/quad +12v for example) somewhat.. ;)

[eva2000]

The problem this adaptor brings is that powering your video cards with seperate power supplies (or even the same one) can cause leaking voltage and current due to different power outputs..


You mean even if main psu powers both video cards ? or just if you power both video cards with 2nd psu ?

[STEvil]

only if you power a video card or other item with external power connection attached through ISA/PCI/AGP/PCI-E.

plugging secondary psu into one of those molexes some of the boards have now could have same result too.

[eva2000]

only if you power a video card or other item with external power connection attached through ISA/PCI/AGP/PCI-E.
didn't understand that ? :o

[drunkenmaster]

well, at the moment i'm using the connector you get in the coolermaster stacker, which is basically a 20-20pin atx extension cable, with another atx connector attached off it only with the green and black wires which goes to the other psu and jumpstarts it. Working fine so far. I'm powering asus sli rig with it, ocz 520 main psu hooked up to dvd, floppy, mobo connectors including eazy plug and the top fan. The other psu, thermaltake 680W i'm using the normal molex lines, there are 4 of them, one connector on each separate line is connected to a pci-e power adaptor(as they use 2 molex's each) to power both cards. I also have the sata connectors powering up the sata drives(3 of them) and all other case fans connected to the spare molex's most via a fan controller. working fine. Ever have a weird issue that when i turn off the ocz psu at the rear switch first the thermaltake boots up :o , so i have to turn TT off first. likewise i turned on the ocz first once and forgot the TT and it booted fine but got to bios and said pci-e cards need to be connected.

[STEvil]

eva - think of it like this: The power and ground planes of the video card(s) or any other cards which use a molex or floppy connector (ide/sata devices do not count) are are connected to the power and ground planes in the motherboard through the PCI/PCI-E/AGP connector.

If you have a voltage differential which causes one power supply to be enough above another you will leak the extra voltage across the AGP/PCI/PCI-E bus (connector).. thats bad ;)

If you have a power deficiency of either power supply amperage will leak across since the path of least resistance will be to the item which "needs" the power.. also bad ;)

[eva2000]

confused me even more LOL

[enzoR]

if 1 power supply has a +12v like of 11.80 and the otherone of 12.1, when you connect the 11.80 powersupply to the mobo, adn the 12.1 to the videocard you have a 0.3v difference that essentially shorts to the 11.80 to the mobo. you can have this problem with the other rails aswell. some videocards dont have this problem though as their current are isolated with diodes

[eva2000]

ah thanks enzoR.. needed an easier explanation hehe

so if 11.80v psu connected to both video cards and 12.1v psu doesn't connect to any video cards but just fans/pump should be fine ?

[enzoR]

YUP.... but it depends which video card it works perfectly fine with some. which card are you useing? dont you think its a bit of a waste to have a 600wpowerstream to power fans and pump? :P:

[eva2000]

2x XFX 6800GT PCI-E with PCI-E adaptors so need to have 4x molex connections for the 2 cards

[ed.howell]

I have 2 OCZ Powerstreams 1 520W for the CPU and GPU and the 470W powers all the hard drives, fans, pump, dvd drives.

I heard that if you power the CPU and GPU with different PSU's that you could screw something up :confused: Is this correct?

[The Virus]

The best solution is to get 2 identical psu just like you would if you want to run raid hd's which is recommended that they are the same exact models.

[DazzXP]

Dual fanless 350w PSU's :D nice and quiet, 350w for board, CPU and optical drives, the 2nd for video cards and hard drives.

[enzoR]

2x XFX 6800GT PCI-E with PCI-E adaptors so need to have 4x molex connections for the 2 cards

i think Shamino was benching 6800 cards with dual PSU's, you might wanna see if he wrote something about that on his article on vr-zone

[enzoR]

The best solution is to get 2 identical psu just like you would if you want to run raid hd's which is recommended that they are the same exact models.

their would always be some kind of diference because the loads are not exaclty the same

[enzoR]

Dual fanless 350w PSU's :D nice and quiet, 350w for board, CPU and optical drives, the 2nd for video cards and hard drives.


would be cool. you gotta remember though that the grounds (outer case's) of both PSUs should never touch if running them in parallel and also not at the socket.

[DazzXP]

Well my Coolermaster full tower case supports dual PSU's and allows them both to be connected to the same motherboard, except they are 20pin only :(

[enzoR]

i think thats for redundant PSUs?

[STEvil]

would be cool. you gotta remember though that the grounds (outer case's) of both PSUs should never touch if running them in parallel and also not at the socket.

no problem with the outer cases touching, they are earth grounded once you plug them into a 3-outlet wall socket.

EDIT

This is the same reason you can use the case or motherboard mounting holes as ground points when testing vmods and stuff :stick:

[enzoR]

They go BOOM when both PSU's share the same ground. thats y their cases shouldnt touch and also 1 PSU must not be connected to a wall socket with ground

[brandinb]

They go BOOM when both PSU's share the same ground. thats y their cases shouldnt touch and also 1 PSU must not be connected to a wall socket with ground

huh?? that doesnt sound right to me....can you clarify why this happens as my understanding is that it shouldnt be a problem
________
blonde girl Webcams (http://www.girlcamfriend.com/webcam/blonde-girls/)

[STEvil]

it isnt a problem.