Molex to PCIe power connector


I recently noticed that I had a somewhat strange setup with my graphics card power connector. My card is X1950pro and it needs some extra power in addition to the PCIe slot, so there's a PCIe power connector on it. However, I noticed I hadn't used the PSU->PCIe connector for it. Instead, it was connected with 2 cables: PSU->Molex female and Molex male->PSU (the latter being connected to the card's PCIe power connector).

Now, I googled this, wanting to know if this was a "legit" setup. I mean, sure, the card's worked fine for 3 whole years, but I was just worried that this way of connecting could have side effects I haven't noticed. A few sources (like this) tell me that you should connect both of the Molex male->PSU cable's Molex ends to the power supply. I however hadn't done this, and I was only using one Molex connector (even though the cable has two of them, being a Y-adapter).

I guess my question is that could this be a problem? I haven't noticed anything wrong with the functionality of the card, but I guess it's possible it hasn't gotten enough power. Can that be damaging? Have I been running the card with less than full capabilities?
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  1. Three years no problems, I really wouldn't care too much. But, in terms of power supply connectivity, it's best to use as few adapters as possible.
  2. There is a very common kind of adapter type for Molex connectors, usually seen in the form of providing power to one or two Molex power consumers (like HDD's). The adapter has 3 Molex connectors on it - 1 is male, to be connected to the female output connector coming from the PSU. The other 2 are female. One is to be used to power your first device with its Molex input male connector, and the other is just a free female Molex ready to be used for something else. You can use this adapter to power one device without "losing" a Molex output from the PSU (because the adapter "regenerates" the one used), OR you can use it to power 2 devices from one PSU output connector.

    It sounds to me as if the adapter that came with your vid card was like this, EXCEPT that one of its outputs was NOT a female Molex, it was a PCIe type specifically designed to fit into your vid car's connector. That way you get power to the card, and still have an open female Molex for some other use. If that's the case, you do NOT plug that loose connector back into the PSU somehow. I'm pretty sure that, of the 2 Molex connectors on that adapter, ONE is male to plug into the standard female output of the PSU, and the other is female to replicate the used PSU output. You could not plug that latter connector into another female Molex output from the PSU.
  3. Thanks for the answer, thumbs up for you both.

    I could've been more clear about the cable I connected to my video card. Here's a picture of a similar one, so there are 2 male Molex connectors.

    However, I did some digging and confirmed it came with my graphics card and not, say, the PSU, so it was indeed intended for the card. The manual that came with the card is rather poor and doesn't really say if I should've connected both of the Molex ends to a power supply. I guess it doesn't really matter since I haven't noticed any malfunctioning, but do you think it would have a positive impact on the performance if both of them were connected?

    Anyway, thanks for helping clear this up.
  4. i use one of those. they are supposedly not amazing but i think its nothing to worry about. if it has worked for u so far then its fine. of course, if ur psu already has a 6pin pci-e connector then use it by all means, but if it doesnt then that setup will be fine!!!
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