Reddit reviews StarTech.com 6in SATA Power to 8 Pin PCI Express Video Card Power Cable Adapter - SATA to 8 pin PCIe power

This.

Or this.

It doesn't look like your power supply is modular because those Corsair PSUs use ribbon type cables.

These types of cable adapters are usually frowned upon. They tend to be very cheap in quality and have been known to start fires. Many people buy a power supply designed with at least two 6+2 pin PCIE power cables instead of using cable adapters.

Consider this.

Yeah, I had plans to use my 1070 in my next PC build in August, but use it in my current PC build until I get the rest of the parts, so then I can sell my old graphics card to a friend of mine.

Right now I am using an AMD Athlon X4 860K (Yes I know that the CPU is a big bottleneck to the GPU), and I don't have it overclocked. Is there any way that I can temporarily underclock the 1070 to take up less power, so then using it is a possibility?

Here is the power supply I have plans on buying for my next PC build, but may buy next month: https://pcpartpicker.com/product/R2mxFT/corsair-power-supply-cp9020103na

Also, here's the adapter thing I bought initially:
https://www.amazon.com/gp/product/B007Y8FSMQ/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Those are PEG 6 pin and PEG 6+2 Pin connectors. You can use adapters like this 6 pin and this 8 pin to get some extra of these if your power supply does not provide any more. Each will consume two SATA power connectors (molex versions are also available). But most of all, make sure your power supply is strong enough to handle those cards and your system.

splitters or adapters.

https://www.amazon.com/StarTech-com-Power-Splitter-Adapter-PYO4SATA/dp/B0086OGN9E

https://www.amazon.com/Branded-8inch-15pin-Express-Power/dp/B005NJXY7O

https://www.amazon.com/StarTech-com-SATPCIEX8ADP-6-Inch-Express-Adapter/dp/B007Y8FSMQ

You might could try unplugging your optical drive, and running an adapter from whatever powers the optical drive to the 8 pin power connector for the card.

If your PSU can support the wattage, of course. Which for a low-end card, it probably can.

Something like this.

These are the ones i got, i haven't gotten 8 pins to 8 pins YET. https://www.amazon.com/gp/product/B007Y8FSMQ/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B01DV1Z32Y/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

I think you need something like this https://www.amazon.com/StarTech-Express-Power-Adapter-PCIEX68ADAP/dp/B007Y8FSMQ?th=1

You can get SATA power to 8 pin psu adapters that work fine. I would make sure it’s one that uses two SATA power connectors, not just one.

like this at Amazon for example

That's the problem with these macs... (I have a 4,1 as well)
You may be able to find a wire that will adapt from the sata port to the 8-pin. another option is finding some sort of external psu.

http://www.amazon.com/StarTech-com-SATPCIEX8ADP-6-Inch-Express-Adapter/dp/B007Y8FSMQ

Personally, I wish someone would manufacture an adapter for a modular power supply that could replace the stock apple one.

Have any extra SATA connectors? Could run two of these.

People will shit talk these because risers catch fire over faulty converters and bad grounding. Just be safe about it and you'll be fine.

Edit: Forgot to mention using a second PSU, but did so here.

Damn I'm stupid, that's exactly right for the SATA cable. Is this the correct power cable?

Edit: Nevermind I've got it. The current HDD has an 8-pin PCIE that has multiple SATA connections on the one wire. This explains why the motherboard didn't come with any spare wires. All I need is the SATA cable you have pictured there. Cheers!

You have options if you still have 8-pin power slots open on your PSU. Hard drives don't use much power; rails shouldn't be a concern.

• https://www.amazon.com/Power-Express-Video-Cable-Adapter/dp/B007Y8FSMQ
  
• https://www.amazon.com/Cable-Matters-2-Pack-SATA-Power/dp/B01DV1Z4X2
  
• https://www.monoprice.com/product?p_id=8494

7/15 is Friday, today is 7/12

Also try this:
https://www.amazon.com/StarTech-com-SATPCIEX8ADP-6-Inch-Express-Adapter/dp/B007Y8FSMQ?ie=UTF8&*Version*=1&*entries*=0