I just bought a Rosewell RC-508 pcie card for additional rear USB ports, and it has an (optional?) secondary power connector that is molex. My modular PSU does not come with any kind of molex adapter, so I'm wondering what is the best way to draw power from the PSU using a converter? I still have a number of connections open on the PSU, including peripheral, VGA, even another CPU. Does each connection vary in output voltage? Which connector on the PSU should I use to power this card? I'm not finding a ton of molex adapters online, and the ones I am finding are 1x6pin (or 8pin) to 2xMolex. I don't have any other molex devices, but i suppose I could split off some of my 3-pin fans with a molex adapter if that would be better than running them off the board on 3/4-pin Y-splitters.
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How to power add-on USB card
- Thread starter fatryan
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Wouldn't i still then need a sata to 6/8pin adapter to get to the PSU?
Tsumi
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Molex carries 12v and 5v. 3-pin fan, VGA, and CPU connections are 12v only. SATA has 12v, 5v, and 3.3v.
If you don't have any free SATA connections, get a SATA splitter and a SATA to Molex adapter.
If you don't have any free SATA connections, get a SATA splitter and a SATA to Molex adapter.
So does that mean that sata is the only option? Or does it depend on the device (e.g. a molex-powered card that requires 12v only)?
I'm not sure if i even have another sata connection on my PSU. I'll have to check. But i already have 2 SSDs, 2 HDDs, and an optical drive all running on sata power. The SSDs are on a splitter and the HDDs (and possibly optical drive too) are on a splitter. How many times can you split a sata connection?
Tsumi
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Looked up the card and it doesn't say whether or not it needs the 5v. If it is capable of running off of the PCI-E slot only, then it does not need 5v.
I read somewhere which seems to suggest it might only need the added power on very power hungry devices. Obviously I'm going to try without first, but i wanted to be prepared in case. I'm mostly going to be using these ports for low power peripherals like my wireless mouse transmitter, UPS communication, maybe a tablet and/or phone charger if it's high speed. I have a 3.2 Type A and 3.2 Type C on my board's back panel for any data transferring I might do. This was just a cheap way for me to power all this other crap I got plugged into the front panel or monitor ports at the moment.
Actually, looking at the specs on EVGA's website, looks like my PSU has 4 sata ports and 4 sata adapters, so I may not actually have an issue there.
Do you happen to know of any sort of guide for what devices can be powered off what PSU ports? That would make this a lot easier lol
In my experience, the connectors are fairly fool proof. If they physically plug together they should be fine. Doesn't hurt to double the manual for everything just to make sure.
I was reading about some issues with fires in some adapters lol
So I just stopped home for lunch cause i forgot my mask, and I checked out my PSU and available adapters real quick. Apparently I do have 2 EVGA 6-pin (perif) to 3xMolex adapters that came with the PSU. I swore i looked for a molex adapter before for a fan and couldn't find one. Anyways, should I not use these on the USB card because of the voltages? I ordered the molex to sata adapter already, and i might as well just keep it since it's only a few bucks.
Tsumi
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The PSU side connection is not the same as the GPU or motherboard side connections. There is a reason modular cables are specific to the PSU line, and should not be mixed between different PSU lines and especially between different manufacturers. EVGA will put the proper power on the PSU side to supply power to the molex and SATA connectors.
I'm not sure I follow what you're saying. I mean, i get that the PSU ports and adapters are manufacturer-specific. My googling this morning led me to that conclusion already. So I'm not trying to find a replacement for one of my EVGA adapters.
But when it comes to the device end of my PSU adapter, am I not supposed to use it for this USB card? Is the 6-pin to 3xMolex adapter supplied by EVGA not supposed to be used on a USB card? If no, then what can it be used on and how do you tell if it will work with any given device? If it were merely about voltages, you'd think the equipment specs wouldn't be so hard to find...
Tsumi
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I think you're confusing yourself and making this more difficult than it should be.
If EVGA has a cable for your PSU that goes out to molex, it is providing the correct power for any molex device. If you're talking about a 6-pin PCI-E to molex adapter, the only thing that molex adapter will get is 12 volts on the 12 volt pin because PCI-E only supplies 12 volts. However, the adapter will also be configured to not supply anything on the 5 volt pin. EVGA 6-pin PSU side connector is not the same thing as a 6-pin PCI-E connector.
This is very likely the case lol. I'm very much an amateur.
Ok, i got it. I guess I was causing the confusion by using incorrect verbiage. I just assumed that "6-pin" or "8-pin" was just kind of like a generic term for the number of individual electrical connectors in a given connection. Though my EVGA adapter only actually has 4 electrical leads in those connectors. The other 2 are empty. Guess that makes sense for a molex connection. Thanks.