Powering graphs card over 75W without 6-pin or 4-pin on Motherboard

Hello,

Is there any way to power a PCIe graphics card over 75W with a 6-pin connection on a motherboard without a 6-pin connection and no available 4-pin connections?

Not really too sure what you are asking. If you have a GPU that requires a 6-pin connector you need to get a 6-pin into it. You can do that with adapters.

If you have NO available 4-pin connectors? (I assume you mean Molex?), then I think you might want to look into a GPU upgrade. You can get cheap good ones for around the 20 dollar mark.

On the motherboard? Do you mean on the PSU?

Molex to 6-pin is the adapter you need, if you dont have any molex connections available then you need a new PSU.

You are talking about the 4 or 8 pin connector on the motherboard that will help it power video cards. I am not sure if there is a converter cable from a 6 pin to a 4 pin to do what you are talking about.

Thats sort of what I thought, wasn't sure if someone made a USB to 6-pin adapter or a PCIe slot to 6-pin adapter/passthru.

http://h18000.www1.hp.com/products [...] 77_na.html

USB provides only a few watts of power so you really shouldn't try to power anything with it unless it was designed to be powered by USB.

You can get a Molex splitter (a Y cable) and then a molex to 6-pin PCIe, but I wouldn't recommend it unless you want to do the work and figure out how much power is being put through the wire that connects the Molex plug to the PSU (since there are typically multiple molex connectors all attached to the same wire going to the PSU). If you draw too much power over an 18 gauge (I believe that is the correct gauge) wire you are risking a fire.

If you had a free cable with molex connectors not doing anything then I'd say a molex to 6-pin pcie would be fine.

Sorry, thanks for the help, but I'm guessing I'm not making it clear, no molex connectors at all, none in use, etc, please look at link above for system information.

Am I missing something here? Out of connectors, so replace the PSU?

I found two Molex splitters within arms reach of my desk, and I have a whole drawer full of them across the room. They're cheap and not hard to find. I imagine it would be a heck of a lot cheaper and easier to try one of those rather than to replace the whole PSU just to get another connector.

EDIT: Wow, I gotta spent less time proof-reading. Somebody got it saying it before me while I was spell-checking . . .

that is what I was guessing, but wasn't sure. Yea, I don't know of any solutions for what you want to do. The other option is step down to a GPU that only draws 75W from the PCIe slot.

My Dell PowerEdge 2850 is similar and I wanted to install an HD 5770. In the PE 2850 the dual power supplies are hot swappable.

What I had to do is bust out my volt meter and perform a little surgery. The hot swap power supply had some even number of power takeoffs. With some testing it turned out that I had +12v rails and ground rails. No +5v rails, but that's OK since the 8-pin adapters want +12v.

What I did then was map out the electrical connections required for the 8-pin adapter, and soldered the appropriate wires to either the +12v or ground. It actually wasn't that difficult once I got over the fear of performing the surgery.

So it can be done, but this approach is not for the faint of heart.

One other consideration is the PCIe bus bandwidth. On my server it's only PCIe 8x. Some research I did awhile ago told me that anything more than an HD 5770 might saturate the bus and provide diminishing returns, YMMV.

Finally, in Dell's case, I ran into a situation where Dell may not actually provide the full 75 watts to their PCIe bus. Check your server specs carefully to see if HP gives you what you are expecting.