Hi,
I have 3x R9 290x and 2x R9 290 on Z97 GAMING 5 motherboard.
4 of them are connected with riser x1 -> x16 from motherboard x1 slot.
I want to connect 5th with riser x1 -> x16 from motherboard x16 slot, but doesn't work.
I checked riser, electricity, test on other slots evertything and and it works.
I tried to unplug one x1 riser and there are only 3 GPU detected.
I'm using windows 7
Any ideas?
It's not (yet) probelm in too much GPUs... that doesnt solve the problem 
Bad riser is my guess
No, it works on x1 slot
Same issue on Gaming M5, Windows 10
not sure if it will help but try re-installing your drivers after using DDU to uninstall them
boot up with 1 GPU in, then restart and add another or a couple more and keep going until they are all (hopefully) detected
One of two issues here...
A faulty riser. Look at the 1X PCI side and make sure all solder points on the back side of the board are solid looking. Most of the time these are corroded and touching in some instances. Poor QC with most brands found on eBay and Amazon. Try known working ones to verify the card is not at fault.
The gaming 5, at least in my 4 rigs, needs some modification in the bios to allow for up to 7 cards. Due to PCIe lane bandwidth I typically change my PCIe speed settings to Gen1 in bios along with 8x4x4 and 96 latency. Also change graphics mode to from IGP to PEG. But, you will have to plug your monitor into one of the graphics cards. You can also disable on board audio if you want. Try this along with making sure all risers are intact.
On a side note, keep trying different configurations and risers. Sometimes mobos can be finicky and need several reboots to recognize GPUs properly (at least with the way we build out these rigs). With that mobo as well you can check to see if the GPU is being detected via the hardware monitor in the bios. If you dont see it there, windows will not see it either. Once you see it here, if you are having driver issues (error 43, etc) than you can start messing with them.
Use USB riser. Riser with ribbon will not work in 16x slot (on many motherboards).
my advice is never use ribbon risers ..buy the best
I solved it.
I pluged riser into 3rd one x16 slot, connect hdmi to monitor and unplug another GPUs and I get picture, boot to windows 7 and add another 4 one on next reboot.
But with win 7 i got 4 gpus and 1 with yellow !.
I try to use mod but didnt work, so I installed win 10 and now work fine everything after few faults with driver on beggining :).
windows 7 is crapy for mining.. i recomend ubuntu 14 or windows 10
After few hours ( almost frustrated ) I found your "How to"
I fixed following the point 2.
Thank you very much!
yeah this step is important
Gen1 in bios along with 8x4x4
but using gen2 works fine for me and 7 GPUs
without those 2 changes the board has problems detecing more than 6 for me... thats how I origianlly got 7 GPus to work... that and like a dozen restarts and the right AMD drivers
Looks like i have the same issue again, after is added a new XFX 480,
4 x XFX RX480
1 x R9 Fury Windforce
GEN1 and latency 96.
I see all the cards on device manager but only 2 are enabled, on the not working I see this device status :This device cannot find enough free resources that it can use ( code 12 )
Any idea ?
Thanks!
your using a Z170 board? if so the 170 boards are no good for mining, dont use 6th gen boards for mining - hard to get more than 4 to work.
Yes, I thought is there a solution ...
Thanks !
yup solution is stick with 4th gen boards 
code 12 can settle ??