Z87-K PCI-E 1x to 16x Riser slot not working

[wand3r3r]

Does anyone have any idea what's going on here and why the 1x slot doesn't work?

I have an Asus Z87-K board since I wasn't planning on using multiple PCI-E slots on this board and it was about all Microcenter had at the time.

It has 2x PCI-E 16x slots, and 2x PCI-E 1x slots.

The first 1x slot is shared with the 2 PCI-E 16x slots, and the final 1x slot is covered when there is a video card in the system so it's useless unless everything is on a riser.

Tried so far:
With and without the Jumper wires
http://www.gobitgo.com/articles/1001/How-To-Correctly-Use-and-Install-PCI-E-Riser-Cables/

The risers are powered by a molex connector. I put the second 16x slot into use via the 1x to 16x riser (uses only 1x connection I guess) so the risers are verified to work.

Initially I had a problem with getting risers to work, I had to have the riser connected to the same PSU as the PC. I have a secondary PSU for the 1x -> 16x video card, but the riser is connected to the PC's PSU.

The fan turns on 100% but neither Afterburner nor windows see the third card.

1 - 16x = ok
1 - 16x via a 1x->16x riser = ok
1 - 1x (via riser) = no go.

Asus z87-k manual
http://dlcdnet.asus.com/pub/ASUS/mb/LGA1150/Z87-K/E8191_Z87-K.pdf

 

[TheStu]

Did you get the riser cable with the 12V power lead? PCIe x8 & x16 slots provide up to 75w of power to the card on their own. But, anything smaller than that only provides up to 25w.

 

[wand3r3r]

Yeah it has a 4 pin molex power cable in the style of the hdd or DVD drive power cables.

 

[TheStu]

Yeah it has a 4 pin molex power cable in the style of the hdd or DVD drive power cables.

Man, I totally missed that the first time around... sorry.

So the slots on the board are laid out like this:

_
IO
IO
IO
_

x1 Empty?

x16 > GPU

x1 > x1-x16 riser > GPU (no work)

x16 > x1-x16 riser > GPU (work)

Try swapping x1 slots. According to the manual, both x16s, and the first x1 are on the same IRQ assignment, which used to make a difference, many many moons ago, when I better remembered what that meant.

Also, I assume that this is for mining, since that's just what everyone is doing these days, but I would suggest putting an x8-x16 riser into the second x16 slot, more bandwidth that way.

 

[Emulex]

10watt maximum power draw from x1 slot, 75 watt from x16 slot

 

[wand3r3r]

Man, I totally missed that the first time around... sorry.

So the slots on the board are laid out like this:

_
IO
IO
IO
_

x1 Empty?

x16 > GPU

x1 > x1-x16 riser > GPU (no work)

x16 > x1-x16 riser > GPU (work)

Try swapping x1 slots. According to the manual, both x16s, and the first x1 are on the same IRQ assignment, which used to make a difference, many many moons ago, when I better remembered what that meant.

Also, I assume that this is for mining, since that's just what everyone is doing these days, but I would suggest putting an x8-x16 riser into the second x16 slot, more bandwidth that way.

1x = doesn't work
16x = works
1x = under the 16x above when in use
16x = works, works with a 1x -> 16x adapter too.

The issue with swapping 1x ports is that then I would need the first 16x to use a 1x adapter to "raise" the card so I can fit the 1x adapter. I believe that first slot is the "primary" gaming card so I don't think I could play at all if I put it through a 1x adapter just to raise it out of the way of that 2nd 1x slot. I should almost try it just to see.

I could also try get a 16x riser to raise that first 16x slot to get access to the 2nd 1x slot.

10watt maximum power draw from x1 slot, 75 watt from x16 slot

Does that mean that the 1x slot shouldn't work at all? I would think it could work when idling at least since it doesn't need much power and would be connected to a secondary external PSU.

---

I'm thinking I should just upgrade to a MSI Z87-G45 or G55, or possibly a Gigabyte D3H or similar with 5-6 PCI-E slots.