Molex cable power draw

[Me1z]

Is there a limit on how much power can be safely drawn through a single molex power cable? Most cables have up to 4 connectors daisy chained together, but this doesn't necessarily mean its safe to have any 4 molex powered components drawing from the single cable. I know normal hard drives/ssds only use 6-10 watts each, but I'm looking to power 6 65W components with as few cables as possible.

[coen113]

6 65 watt components? do you have a good sized power supply?

[Me1z]

6 65 watt components? do you have a good sized power supply?

 

I'm looking for a good PSU in the 550-650W range based on what calculations I've done myself, but temporarily I will have this running off a Corsair AX1200 that I use for my test bench. Limited number of molex/sata power cables on psu's is actually why I'm asking. most modular psu's in the 550-650w range only have room for 3-5 molex cables.

[coen113]

I'm looking for a good PSU in the 550-650W range based on what calculations I've done myself, but temporarily I will have this running off a Corsair AX1200 that I use for my test bench. Limited number of molex/sata power cables on psu's is actually why I'm asking. most modular psu's in the 550-650w range only have room for 3-5 molex cables.

what do you want to power?

[Me1z]

what do you want to power?

 

6 GTX 750tis plugged into 6 of these:

 

The GTX 750tis have no extra 6pin connector and the riser is designed to take no power from the motherboard, so it takes what power it needs from the molex connector. The GPU has a TDP of 60W and you need to allow a bit more for vram etc, so 65w is a good estimate.

[BrightCandle]

As far as I know molex is good only for 11A (https://en.wikipedia.org/wiki/Molex_connector). If you have one with 18 AWG wire then the wire can survive 16A but the pin might not cope with it. Seems like the molex connector can pass enough power for what you are wanting to do, assuming the motherboard can deliver the amps down the molex completely and not reserving a lot of the 12V amps PCI-E connectors.

[PassionFruit]

6 GTX 750tis plugged into 6 of these:

 

The GTX 750tis have no extra 6pin connector and the riser is designed to take no power from the motherboard, so it takes what power it needs from the molex connector. The GPU has a TDP of 60W and you need to allow a bit more for vram etc, so 65w is a good estimate.

Is that for mining?

[Me1z]

As far as I know molex is good only for 11A (https://en.wikipedia.org/wiki/Molex_connector). If you have one with 18 AWG wire then the wire can survive 16A but the pin might not cope with it. Seems like the molex connector can pass enough power for what you are wanting to do, assuming the motherboard can deliver the amps down the molex completely and not reserving a lot of the 12V amps PCI-E connectors.

I know that it works for at least one GTX 750ti, because I have one running right now. My problem is a shortage of molex connectors, and I'm not sure one cable could handle 2 of them. Is there a way of finding the amperage and voltage of my GPU?

[Me1z]

Is that for mining?

 

Close, but no. It's for Folding. Kinda like mining, except you are calculating molecular physics to help find cures to diseases rather than algorithms for money.

[PassionFruit]

Close, but no. It's for Folding. Kinda like mining, except you are calculating molecular physics to help find cures to diseases rather than algorithms for money.

Ah, okay then.  

[BrightCandle]

Here are the basic numbers.

 

A PCI-E card with no addition plugs that is 16x can use up to 75W TDP, electrically for short bursts it can pull more than that, to the tune of about 150W but its longer term (as in 1 second) can't exceed 75W.

 

A Molex can delvier 12x11 = 132W

A 18 AWG cable can deliver 16x12 = 192W

 

A 750ti consumes 60W long term as confirmed by reviews.

 

It sure looks like it just about fits to me.

[Me1z]

Here are the basic numbers.

 

A PCI-E card with no addition plugs that is 16x can use up to 75W TDP, electrically for short bursts it can pull more than that, to the tune of about 150W but its longer term (as in 1 second) can't exceed 75W.

 

A Molex can delvier 12x11 = 132W

A 18 AWG cable can deliver 16x12 = 192W

 

A 750ti consumes 60W long term as confirmed by reviews.

 

It sure looks like it just about fits to me.

 

Based on that it does look like I could power 2 cards with one cable, or at least wattage wise. Should I be concerned about the amperage? When components are daisy chained together does the amperage add together?