I think all of the cables I have seen so far are pretty much the same, I have never seen anything specified as a SATA I or II cable - further, I don't think the color means much either, kind of like network cables that come in grey, blue, white, yellow or what ever. I have never seen those colors though, I usually see red and sometimes black but the black ones I have seen look kind of cheap - use the one that appears more robust!
I think I prefer the ones with right-angle necks. The mobo side almost always seems to need a straight shot, and the drive almost always seems to need a 90-degree angle (at least to make it look right and to relieve stress on the cable).
At first i thought thats what he was talking about too but he specified cables in the tag-line.
If that is the case, then you might have two different interfaces though the jacks themselves are not manufacturer specific. It may be the case that the raid interface runs on one color but not the other. Check your MOBO maual for what each color means, if it doesnt specify, then dont worry about it. If they are in fact specifying which are RAID and you arent running RAID, then once again dont worry about it.
I just checked the manual that I have for that type of mobo, I believe that the manual said that the purple jacks are running off of the gigabyte raid controller, and the yellow ones are running off the the intel chipset. I dont think it will matter which color you plug it into, although I assume one or the other might have better performance, since they are different.
How many hard drives do you use? I've read people complaining about the fact that it gets hard to use right angled ones if you have multiple drives. Then again, I've heard a lot of stuff and most of it isn't true.
As for which one to plug into, no clue. Just pick one.
had the same question as you and did some research with no def answer a few weeks ago. I tried using both and have not noticed a difference in the gigabyte vs intel when not using raid. Currently using the intel. I dont really think it matters. hope that helps ya