PSU with no 6-pin PCI-E to power 2x6-pin GPU

[Loktar Ogar]

Hi All,

I plan to upgrade my old GeForce 9600 GT 1GB 256-bit to a not so new card that uses 2x6-pin PCI-E like GTX 460 or Radeon similar video card. I currently use (1) 2x4-pin molex to 6-pin from two different 12v rail to power my GPU and it works with no problems.

Now, i wonder if can power up the other GPU the requires 2x6-pin... I still have unused 2x4-pin molex from 2 different 12v rail that was hooked up on my current GPU and planning to add another 2x6 molex to 6-pin, so that makes (2) 6-pin PCI-E's.

I have limited funds so i'm not open to buy a new PSU or other newer video card. The card i'm getting is just a spare from my friend.

I just wanted to know if this is possible or if someone had tried it before? I've already looked in google but they always suggest to buy a new PSU but that is not the plan.

Some suggest to use this StarTech Model PCIEXSPLIT6 6" 6 Pin PCI Express splitter:

http://www.newegg.com/Product/Product.aspx?Item=N82E16812200935


This is my PSU:

http://www.zumaxpower.com/products/zu550w.htm

Similar to this one but has no PCI-E connector.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817101021


Your thoughts are highly appreciated.

 

[trnddwn33]

If the 2xmolex connections are actually on different rails you will probably be fine using molex-> 6pin adapters. If all the molex happen to be on one rail you might have issues. Generally the adapters work fine if there is enough power there.

 

[Loktar Ogar]

Yeah, i've tried putting the 2xmolex on a single rail once and it did not work out on my 9600 GT and i've noticed right away the purpose why there are 2xmolex's. lol

I hope someone can confirm right away if the plan above is possible.

 

[Goodeggray]

The psu has 2 rail each having 20A. How many molex outputs are there?

 

[delluser1]

2 x 20a 12v rails, a 50a 5v rail and a -5v rail
No pcie connectors
Don't know if you realize this but that psu was designed for a different era in time

A little hint about the 12v rails ; typically 1 is for the cpu, the other is for everything else, unless you tie in the ATX/EPS connector you're only using 1

 

[w1zz4]

It should work if the PSU is able to deliver rated amps, but this PSU should be on the near future upgrade list... It's unfortunately a cheap unit that may not be able to stands the written specs...

 

[4745454b]

I'm not sure what you hope to gain from posting this. You already said buying a PSU isn't an option, nor is buying a better card because you are getting this from a friend. And judging from what you've wrote I'm not sure you have a real idea as to how PSUs work, etc.

My general advice is to never use adapters. Ever. If the people who made the psu wanted you to have PCIe plugs on there they would have done that. There are a few exceptions to this such as high powered units that existed before PCIe came about. The problem is that was so long ago those units should be retired by now. But of course you don't want to/can't buy one so telling you need need to upgrade if you want to use TWO adapters is a bad idea on my part. If this is really a friend then see if you can test it first. Wire it up, try to play a game. But in my mind you will really be pushing that old PSU. My advice is to keep saving and get a better PSU.

 

[Goodeggray]

Seems like one rail is for the cpu and mobo and one for peripherals. I would chance it.

 

[delluser1]

Seems like one rail is for the cpu and mobo and one for peripherals. I would chance it.

Seems like and is are 2 different things
It's a rare occurrence but it does happen, the OCZ MSXP is an example, really don't know about OP's, why I said "typically"
Usually the seperate "rails" will be signified by stripe on the insulation, easy way to find out what's what

 

[4745454b]

Right. (and even then not always.) But judging buy the OPs writing I'm assuming when he tried a "single rail" it was just that he tried two "molex plugs" on the same bit of wire. I mean to disrespect to the OP, but he really needs to upgrade the PSU before worrying about putting a 150W+ GPU in there.

 

[Loktar Ogar]

Thanks to all who replied, all replies are appreciated.

I'll give it a shot and if it worked i'll post it here. and hopefully i'll get an upgrade soon for a better PSU... or a GPU upgrade with only one PCI-E or just use GTX 650 Ti...

 

[Loktar Ogar]

Best answer selected by Loktar Ogar.

 

[djscribbles]

You should upgrade the PSU when you can, regardless of whether you get a new GPU that doesn't need 2x6pin, the connectors aren't really the problem it's the PSU itself that is suspect. A cheap PSU like that can cause damage to your computer if you are unlucky by operating out of voltage requirements while 'working' normally, or surging power to components when it fails.

This is a helpful (not definitive) list for shopping around: http://www.eggxpert.com/forums/thread/323050.aspx , search for reviews from whatever you choose to buy on Jonnyguru/hardware secrets etc (don't go by newegg reviews, because no end user really has any idea how good their PSU is unless they have an electronics testing lab at home).

If you get a quality 600w psu, it should be powerful enough to run any single GPU for the forseeable future.

 

[Maziar]

This topic has been reopen by Maziar

 

[Loktar Ogar]

Thanks Maziar! I just need to update this thread as promised.

Update:

I got it working on my current PSU. I ran it with FurMark and MSI Kombustor burn in test with no errors or problems. Also, i've noticed on the label on my PSU, it stated that the combined 12v1 and 12v2 = 38A. So, i think my PSU can really handle it! Been using it for almost a week now and my only problem is the heat that the new card is producing