4 pin Molex to 8 pin PCI

[DawgBone]

I'm interested in an ASUS NVIDIA GeForce GTX 570 for my 3.1 MP. It needs one 6 pin and one 8 pin power connection.

I was thinking about using the Molex connection for the 2nd optical drive and found these converter cables:

4 pin Molex to 6 pin PCI:
http://www.amazon.com/4-Pin-Molex-Female-Adapter-Length/dp/B007NMSUUA

6 pin PCI to 8 pin PCI:
http://www.amazon.com/StarTech-Express-Power-Adapter-PCIEX68ADAP/dp/B001TK3TJY/ref=sr_1_1?s=electronics&ie=UTF8&qid=1366483159&sr=1-1&keywords=6+pin+to+8+pin

I wasn't able to find a 4 pin Molex to 8 pin PCI.

Has anyone tried this before? How did it work for you? Thanks.

 

[handheldgames]

Wrong connector. I haven't found anyone anufacturing a cable with the proper connector. You could modify a standard Mac Pro pci-e power cable for the task. I have a post in this forum detailing the specifics.

I'm interested in an ASUS NVIDIA GeForce GTX 570 for my 3.1 MP. It needs one 6 pin and one 8 pin power connection.

I was thinking about using the Molex connection for the 2nd optical drive and found these converter cables:

4 pin Molex to 6 pin PCI:
http://www.amazon.com/4-Pin-Molex-Female-Adapter-Length/dp/B007NMSUUA

6 pin PCI to 8 pin PCI:
http://www.amazon.com/StarTech-Express-Power-Adapter-PCIEX68ADAP/dp/B001TK3TJY/ref=sr_1_1?s=electronics&ie=UTF8&qid=1366483159&sr=1-1&keywords=6+pin+to+8+pin

I wasn't able to find a 4 pin Molex to 8 pin PCI.

Has anyone tried this before? How did it work for you? Thanks.

 

[bax2003]

Tried on my ex MP 3.1. ASUS GTX570 Direct CU II (6pin + 8pin), with two standard Mac Pro 6 pin PCIe booster cables and one of them converted to 8 pin with adapter like that. Everything was fine.

 

[DawgBone]

Tried on my ex MP 3.1. ASUS GTX570 Direct CU II (6pin + 8pin), with two standard Mac Pro 6 pin PCIe booster cables and one of them converted to 8 pin with adapter like that. Everything was fine.

Thanks, Bax.

----------

Wrong connector. I haven't found anyone anufacturing a cable with the proper connector. You could modify a standard Mac Pro pci-e power cable for the task. I have a post in this forum detailing the specifics.

I'll check it out. Thanks.

 

[DawgBone]

My revised strategy is to use a 4 pin Molex to 6 pin PCIe adapter to tap into the ODD Molex connector:

http://www.amazon.com/4-Pin-Molex-Female-Adapter-Length/dp/B007NMSUUA

Then use a 2 x 6 pin to 8 pin "Y" adapter to connect with the video card:

http://www.performance-pcs.com/catalog/index.php?main_page=product_info&products_id=24552

One of the 6 pin sources for the "Y" adapter will come from the motherboard using this:

http://www.ebay.com/itm/Mac-Pro-PCIe-PCI-Express-6-Pin-Video-Card-Power-Cable-/270475251874?rt=nc&_trksid=p2047675.m1851&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D15054%26meid%3D7121197603607773331%26pid%3D100005%26prg%3D1125%26rk%3D4%26sd%3D261188102053%26

The other will come from the Molex adapter.

HandHeld's approach is more elegant, since you would not have to thread a cable from the ODD compartment:

https://forums.macrumors.com/threads/1566436/

But I really don't want to fabricate my own cable. Does anyone see any problems with this? Thanks.

 

[handheldgames]

The connector you are showing is the wrong size. Thats a P4 ATX power connector... Just a bit TOO big for a fit. I have extras here if you need any You will be pleasantly surprised to find out that the MacPro connector is a (going from memory here) mini-fit jr molex 4 pin dual row hanging connector:

http://www.molex.com/molex/products/family?key=minifit_jr&channel=products&chanName=family&pageTitle=Introduction

Hope this helps. I don't want to make my own cables either, I just may once I get past this crazy programming deadline.

My revised strategy is to use a 4 pin Molex to 6 pin PCIe adapter to tap into the ODD Molex connector:

http://www.amazon.com/4-Pin-Molex-Female-Adapter-Length/dp/B007NMSUUA

Then use a 2 x 6 pin to 8 pin "Y" adapter to connect with the video card:

http://www.ebay.com/itm/NEW-PCI-E-8-PIN-Y-SPLIT-2-6-PIN-PCI-E-POWER-CABLE-12-MADE-USA-/261188102053?_trksid=p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D21%26pmod%3D290778077889%26ps%3D54

One of the 6 pin sources for the "Y" adapter will come from the motherboard using this:

http://www.ebay.com/itm/Mac-Pro-PCIe-PCI-Express-6-Pin-Video-Card-Power-Cable-/270475251874?rt=nc&_trksid=p2047675.m1851&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D15054%26meid%3D7121197603607773331%26pid%3D100005%26prg%3D1125%26rk%3D4%26sd%3D261188102053%26

The other will come from the Molex adapter.

HandHeld's approach is more elegant, since you would not have to thread a cable from the ODD compartment:

https://forums.macrumors.com/threads/1566436/

But I really don't want to fabricate my own cable. Does anyone see any problems with this? Thanks.

 

[DawgBone]

The connector you are showing is the wrong size. Thats a P4 ATX power connector... Just a bit TOO big for a fit.

Thanks for the reply, HandHeld. I'm clearly missing something here. I'm a hacker, but my ignorance of hardware is truly breathtaking.

This is the ODD connector I was planning on tapping:

Isn't that a 4 pin Molex? Or maybe you mean one of the other cables? My Mac is an early 2008 3.1.

Thanks for your help.

 

[DawgBone]

Well, I've decided to not tap additional power from the motherboard after all.

Instead I plan on adding a supplemental power supply in the ODD compartment similar to what Dr. Stealth describes here:

https://forums.macrumors.com/threads/1520765/

I will probably be installing two GTX 570s or 580s instead of the 680s the Doctor used. They will be used for programming work in CUDA and OpenCL rather than gaming.