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PCIe Power Connector for 150w GPU

M

michis0806

macrumors newbie
Original poster
Aug 18, 2018
6
0
Hi there,

I am currently searching a power-cable to connect a graphics-card with a 8pin power-connector to a Mac Pro. As I learned, the two mini-pcie connectors on the logic board can deliver 75w each. I read a lot of some 2x6pin to 1x8pin cables but cannot find any in German/European stores...

Can anyone point me to a seller that delivers to Germany?
Alternatively: Is it possible to use two mini-6pin to 6+2pin cables and connect 6 pins from the first and the +2 pins of the second cable to the graphics-card?

Thanks a lot!
Michael
 
It's hard to find from europe sellers. If you find one, it's three times the price.
Chinese sellers deliver throughout the world, and mostly without any shipping costs. You will have to wait it for a while though. I have purchased for example from owkeyy_7 and kana1688 (2017-2018) dual 6-pin to 8-pin cables. They are all working cables.

And a couple of little different cables bought too from ouyou2010 and applecable - working cables too. The last one was a 2xSATA power to 6-pin PCIe. It did not set itself on fire, at least not yet.

There are a lot of sellers. I can't remember what was the (by forum users) recommended shop or seller for these exact cables. Maybe try forum search one more time..
 
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Thanks for your help! I'll check them out ;)
[doublepost=1535120623][/doublepost]BTW: I read that the SATA-Ports can provide "up to 54W" in the MacPro. But I didn't find any specs on that. Can anyone confirm that? Is that 54w for each port or for all four ports combined?

Thanks!
Michael
 
I'm not professional at this, I am an amateur. I myself have been warned already, and now you have too: Electricity is not to play with carelessly.

According to specification (wiki) each pin should be able to provide 1.5A. So three connector pins inside the power cable at 12V it would make up to 3x1.5Ax12V=54W per port (watt=amp×volt). That's assuming all three pins are connected, and they all should be, if assuming to get/give 54W max power.

There is more to it though. You would want the cables and connectors and mother board leads to hold up to all of this too. If the hole chain does not hold up to it, something will burn, and you might see flames and smoke. Don't know about the color of the smoke, but I assume blue or grayish. We all are familiar with the electric smell then that bad happens, aren't we.

I bought some 2xSATA power to 6-pin cables, and they worked. They gave me ~2x20W from SATA ports and power an ATI HD 5770 6-pin quite effortlessly. I don't need it anymore, so took it out, and cables too.

You have to take in consideration the heat in those cables. There are these markings in those cables, like 18AWG, FT1, 300V, 80°C, and so on (some American and Canadian standards etc.) They mean something, these can be googled. If they are to be trusted or not, is up to you. The connector ends might as well be the ones to be suspicious about. They are closed, glued, molded, but in some cases they can be examined more easily.

Maybe we should assemble our own cables - at least we would know who to blame after the smoke clears.
 
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Thanks @mikas for this comprehensive answer.
How did you connect your RX 580 pulse to the cMP4,1? is the power from the PCIe bus and the AUX power ports enough?

Thanks
Michael
 
Dual mini 6-pin to 8-pin (+PCIe slot power) is enough for Sapphire Pulse RX580 8GB. There is only one 8-pin power connector in those cards.
 
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