HD 7870/7950 on an OTP406 + Antec NeoPower 650w PSU

[Xile]

I'm having trouble figuring out where the second 6-pin will go since my PSU only comes with 1 6-pin. Both of the cards that I'd like to get are from XFX and are the DD Black Edition models. I'm not sure if the second 6-pin will work on my Motherboard which came with my XPS 420. Which PCI-E or PSU cable would you recommend with the one that I already have? I'm just going to get one card but hopefully my Q6700 CPU will work fine @ 3.2 ghz. I know that Dell's bios is locked but I have used SetFSB and it works fine at 3.0ghz. I know that I will only get a bottleneck at Multiplayer and CPU intensive games like Starcraft II, but since my monitor only supports 1680x1050, I should be fine. So, any idea how I can get this set up to work?

 

[Xile]

HD 7970 and GTX670 are too expensive for me.

 

[delluser1]

Your power supply should have a modular pcie cable as well as the native cable, did ya lose it ?
You'll have to use an adapter or

http://www.moddiy.com/products/Antec-Modular-PSU-Sleeved-PCIe-6%252dPin-to-6%252dPin-Cable.html

Personally, I wouldn't put either of those cards into an older Dell, that's just me
If you want to really get into things you could try a BSEL mod ( Google it ) and maybe take your Q6700 to 3.3

 

[Xile]

Your power supply should have a modular pcie cable as well as the native cable, did ya lose it ?
You'll have to use an adapter or

http://www.moddiy.com/products/Antec-Modular-PSU-Sleeved-PCIe-6%252dPin-to-6%252dPin-Cable.html

Personally, I wouldn't put either of those cards into an older Dell, that's just me
If you want to really get into things you could try a BSEL mod ( Google it ) and maybe take your Q6700 to 3.3

The BSEL mod sounds pretty dangerous for me. I don't want to accidentally ruin my CPU or motherboard in case something goes wrong. Money is not easy to make here and getting the parts is even more of a challenge. I'm from Ukraine, by the way. Well, my PSU does have the native cable. On the ends of the native cable is something that connects to the hardrives. There's also an 8-pin on the native cable. Another PSU cable that is not connected to the native cable has an 8-pin (or maybe it's a 6?) and you can use the other end to connect to more hardrives. Finally, the last cable is a 6-pin to 6+2 Pin or however you call it. Basically, I only have one 6-pin from the PSU which will connect to the GPU, but I need two. Unless there's another way?

 

[delluser1]

Should be a native 6+2 and a modular 6 pin to 6 pin

 

[Xile]

Should be a native 6+2 and a modular 6 pin to 6 pin

Ah, I see the problem now. I have both the 8-pin and the 6+2 as the native, but the two other cables are 6-pin to HDD. Shouldn't there be another 6 pin to 6 pin? I have no idea where it is.

 

[delluser1]

Ah, I see the problem now. I have both the 8-pin and the 6+2 as the native, but the two other cables are 6-pin to HDD. Shouldn't there be another 6 pin to 6 pin? I have no idea where it is.

8 pin EPS native
6+2 PCIe native
Yes, there should be another 6 pin to 6 pin, modular

 

[Xile]

8 pin EPS native
6+2 PCIe native
Yes, there should be another 6 pin to 6 pin, modular

If I were to buy one what would I need to watch out for? Does it have to be a specific model or just a 6-pin to 6-pin?