Some questions about risers and power and stuff

[chibby]

Hello,

I bought a MSI Z77A-G45 Thunderbolt motherboard and currently 2 600W power supplies. I wanted to mine with 4 cards for the beginning. A 7950, 5870 and 2 5850. May add two more cards later and buy a third power supply.
I wanted to rise 3 of the GPUs with x16 to x16 risers unpowered and 1 or later 3 with 1x to 16x which I will modify to be powered.

Will this setup work power wise and everything or will I get some problems with something and do I have to change/modify something?

And are the GPUs ok with getting power from those things?
http://ecx.images-amazon.com/images/I/31qfk1TtfpL._SY300_.jpg
2x sATA --> 6Pin-PCIe


I am really thankfull for every little help.
Greetings

[ssateneth]

use these. they're more reliable.

http://www.newegg.com/Product/Product.aspx?Item=N82E16812198016 $4.50
http://www.outletpc.com/c8182.html $3
http://www.ebay.com/itm/290778077889 $4.50
http://www.eio.com/p-24549-athena-power-cable-ypcie628-6-pcie-6-pin-y-split-to-two-pcie-20-862-pin-cable.aspx?gclid=CO3hivORqrsCFQISMwodUFEATQ $4

putting all that power on 1 12v wire is a bad idea. dont do it. especially for scrypt mining.

[chibby]

Thanks for posting but each power supply will give power to two GPUs. One GPU of these will get power from the PCIe power cable coming directly out of the power supply and only the other GPU will get it with these sata to pcie power adapters. Still not ok?

[ssateneth]

if you like melted yellow wires, the sure, use the sata adapters...

this is what happens if you use sata or molex adapters.
https://bitcointalk.org/index.php?topic=367096.msg3929896#msg3929896

[chibby]

Ok thank you. Just ordered them. Is the rest of the setup fine and should work like I want it to?

[aznatama]

I'll just repost what I said in another post...

Calculate the wattage draw yourself

Each 18ga wire's max amp for power transmission is 2.3A, 20A for chassis wiring as per AWG  (chassis wiring = single wire, better cooling; power transmission = bundled wiring, less cooling)

PCI standard for 6-pin is 75w w/ ~2.05A per 18ga lead wire, and 3 GND wires
PCI standard for 8-pin is 150w w/ ~4.1A per 18ga lead wire, and 5 GND wires

Using molex Y-splitters is possible, but be aware that the fewer wires you use, the more resistance and hotter the wires will get.  Also, shit molex connectors only use 20ga wiring.  If you're going to use molex, you need to ensure that the power draw from your PSU is from MULTIPLE LEADS, and not all coming from one lead (as in the picture above)