Install it in the slots that they say to. The diagram that comes with the motherboard is very easy to read. Slot 1 and 3 (very center that is 60mm spacing) are the x16 slots. I have the z87 Classified, and I think these two work the same. Refer to the quick setup guide and diagram that came with the board.

Wait, maybe it is slot 4. Trying to find you the diagram right now.

It does say 1 and 4 on Hardware asylum. Do you have any other audio cards in, or anything. Are you lanes switched on (only the active lanes you are using). Do you have the 6 pin PCI cable in the bottom left of the board plugged in?

Here is the Hardware Asylum layout for the z87 : http://www.hardwareasylum...vga_z87_classified.png

That connector will be for supplemental power for the PCI-E slots.  You will want to use this if you are using multiple GPU's.  Single or dual set up will not need this per say but can help with stability.

So in the bios where there is a selection for the +12v pcie I choose 6 pin over 24 pin ? I was wondering what that was exactly and what the difference would be. I notice when my 780ti is the only card in (slot 1) it is at 16x then I install the GT 610 and it drops to 8x along with the GT 610. The GT 610 can run at 8x cause it just runs one 19" screen that I use as a desktop extension, no gaming etc is on it, that is my surround (780ti) purpose. So with the 6 pin connected can I install the GT 610 on in any slot now and my 780ti stay at 16x or do I have to install the 610 in the same slot I would another 780ti for SLI and just not connect the bridge? Thanks for the input.

Will do when I get in from work. This board is practically a different animal compared to the Z77 Sabertooth I had.The bios and different areas of customization in it is a world of difference. I really like the board though and the fact I can run two way SLI in dual 16x mode and I think maybe three way SLI in 16x mode. I want to get another 780ti later.
 
**Another question for you, are you running your two SSD in RAID 0 ? If so does it make that much of a performance difference? I have heard it is bad on the drives in the long run. Thank you.

Still getting the same thing even after connecting the 6 pin connector on the bottom left of the motherboard and selected 6 pin for the 12v+ PCI power. I tried it in slot 4 and got 780ti  @ 8x in slot1 and 16x for the 610. Then I tried the 610 in slot 3 and got 8x / 8x

I have only checked it in the bios. I also open E-LEET and look at the mainboard tab and it shows the amount of lanes being used and when the 780ti is by itself is is using 16x 3.0 even at idle or just using internet etc, no gaming. But when I install the 610 it drops to 8x 3.0, no matter which slot I install the 610 in. However, I was told to use slot 1 and 4 in an earlier reply and when I did I noticed the 780ti was at 8x 3.0 in slot 1 and the 610 was at 16x 1.0 in slot 4. Should I swap the cards locations? I have always thought the main card goes in slot 1. Also, I was under the impression this board runs 16x, 16x/16x, 16x/16x/16x, 8x/8x/8x/8x
 
The 610 is a Gigabyte Rev 1.0 card, there is a Rev 2.0, I have no clue what the difference is but both revs are PCIe 2.0 capable. Could the 610 not being the same series/family card cause the drop in lanes used ? If I have to I will get like a GTX 750 and install it, they are only $100
 
I also know the 780ti runs up to four screens. Maybe I am wrong but I just thought the fourth screen would have an effect on performance of my three in surround for gaming. Logically thinking the more screens you use the more resources, energy etc it uses to so I feel it would take away from the surround screens even if minute, I just want to be sure I am getting all the performance possible from the 780ti for my sim racing.
 
It is frustrating but I am sure it will work out somehow. I just find it odd how the Z77 Sabertooth worked without a hitch in this configuration although it was only a 2-3 way SLI board that run in 16x, 8x/8x, 4x/4x/4x but I used slot 1(780ti) and slot 4(GT 610). This configuration run at 16x(780ti) and 4x(GT 610) on that Z77 board. I did notice the 780ti would drop to PCIe 1.0 from 3.0 during non gaming then jump to 3.0 while gaming.
 
Thank you all for all the help and time. 
 
Raymond

Yes, under load this is the numbers. No other cards installed.