Boot problem with more then 5 GPUs and Asus WS-EX99Mainboard

[Refracty]

Hi Octane-Users,
I am setting up a multi GPU system with 6 * 1070s plus 1 * TitanX.
The problem I am running in is that the PC does not boot if I put more then 5 GPUs inside.
No bios screen shows up even after waiting for 2 mins.
First I thought it is a PSU problem but I have tested this with a 1700 W and 1300 W PSU and the problem persists.
I have already tested different risers also some with Molex power cables (so that the PCI sockets draw less power).
Also different CPU energy modes and Gen1 or Gen2 bios settings have been testet.
I have a PCI express power cable next to the CPU and all power connectors are attached with the mainboard.
The mainboard is a X99-E WS USB 3.1 with 64 GB DDR4 Ram. This system is air cooled.
I also tested this without the TitanX but no improvement. Could the mainboard be faulty?
I would really appreciate any tips and help especially by users using the same mainboard and more then 5 GPUs.
Thanks a lot

[ruhney71]

Hi!

I know you tested PSU, but I had a very funny thing with 3* GTX 780 on a sabertooth x79. With 3 cards no boot, with 2 cards a normal boot. Then out of the blue a normal boot with 3 cards. After that no boot.

Tested the PSU and found out that it simply is not stable enough (anymore) when more power is drawn. I replaced it with a identical, but fresh one and all is working now with 3 cards. The faulty old one is now running in a more basic system.

I guess this is not much help to you, since alreayd tested a lot, but I felt I had to leave a note since I found out that big power PSU can appear to be fine, while they are not at full load, or when they have to peak.

Cheers!

[itou31]

Hi,
I know that gimpse (tom) has made a 7GPU (980Ti) with this board (and more power consumption than 1070). I think that you're already activate 4G decoding into BIOS.
So I think also about PSU, could you split power to 2 Power supply to check if PSU or Motherboard ?
I have mine with 4 Titan black inside with one PSU and other PSU with 4 780ti with an asus P9X79 + amfeltec PLX. The Asus X99-E WS has 2 PLX so can handle at least 10 or 11 GPU.
I think also to build another rig with this board and 1080 or 1080ti.

[Refracty]

Hi rouney71 and itou31,
Thank you for your tips.
I will check out the 4G setting and will write tom a pm.
I need to use the rig for production soon so I can not test a different mobo in this case.

[itou31]

Hi, sorry,
it was smicha that build the 7 GPU rig.
Just retreive the post : viewtopic.php?f=11&t=55130#p281798
Hope he can help you.

[Refracty]

itou31, enabling 4D decoding was the solution.
Smicha and Glimpse have also be so kind to point on this.
Thank you everybody.
For all users who are wandering about where to find this feature in the Bios. It is located in the Boot menu.

[glimpse]

happy to help ;) by the way, nice to see more & more 7GPU builds ;)

think 7 is a new 4 =p

[itou31]

Hi,
As some of you in this thread have the Asus X99-E WS, could you confirm some horror stories about this board ?
I would like to buy one with 7xPCIe but not decided yet...
So what to buy with only one CPU board with 7xPCIe ?
Thanks

[oguzbir]

itou31, enabling 4D decoding was the solution.
Smicha and Glimpse have also be so kind to point on this.
Thank you everybody. For all users who are wandering about where to find this feature in the Bios. It is located in the Boot menu.

Nice to see you've sorted it out. I do have an air cooled case and gpu's.

Since the problem is not the risers. Can I ask what brands are you using for PCIe risers? is it possible to share a link.
I'm thinking of adding 2-3 cards to that board as well.

thanks

[glimpse]

Hi,
As some of you in this thread have the Asus X99-E WS, could you confirm some horror stories about this board ?
I would like to buy one with 7xPCIe but not decided yet...
So what to buy with only one CPU board with 7xPCIe ?
Thanks

hi there ;) Yes, indeed this board is pretty picky & some users had some weird issue, however I also helped to speck several builds (7single sloted, seven on risers, 3 on board + 4 in eGPU) based on this board & all of them works as they should. However As Sebastian told, I seen some other stories that come down to the point: it's incredibly powerful & complex board, but with more part under the hood it has more points to fail as well. If You would like to stick with x99 platform You have just a handful of cards that would have 7 physical slots, but if You're not decided yet, then looking for server oriented motherboard might be an option as well.

closes option to mentioned board would be AsRock X99WS E.