OTOY Forums

Hi, I have configured my new workstation, but am having trouble getting all 4 980ti recognized in windows. I am using riser cables to elevate the GPUs so I can install other devices in all available slots. Currently I am able to get up to 3 cards working but the 4th either doesn't show up in device manager or shows up as generic VGA device. Sometimes windows will not boot saying it encountered an error before I am able to reach the login screen, and once in awhile the computer hangs on POST.

Motherboard - ASUS z10pe-d8 ws

CPU - 2x 2697v3

GPU - 4x EVGA 980ti SC

128 GB ecc RAM

256 samsung 950 pro

1.2 tb intel 750

ATTO 10GBE

The computer works fine without the riser cables (4 GPUs in, all recognized) I have gone through booting the computer one by one to find a faulty cable but have had no luck. I have windows 10 installed in full UEFI mode. What could be causing these issues? Thanks for your help.

Hi T,
What is your riser spec?
Seeker

They are PCIE 3.0 x16

I have 3 of these: http://www.thermaltake.com/Chassis/Acce ... design.htm

and one of these (needed length): http://www.moddiy.com/products/Premium- ... cm%29.html

They are not powered but my motherboard has an additional 6 pin power connector for installing multiple GPUs

1. Have you tried it without the ATTO?
2. Do you have 'above 4G encoding' in the BIOS enabled or disabled?
NOTE: While most of us have no prob with this setting there are some reports of mobo's not allowing bios access after the setting. I suggest setting this and then trying the cards WITH the risers one by one. Also have a USB bios ready to flash if need be.

Seeker

Hi there =) with 4GPUs & this motherboard..get rid of cables & add all cards on motherboard directly. test thigns out. You will know if cables make any influence & I bet they do =) price matters least, as 100$ cables do not work for some users while doing completely fine for others. Ideally, You should have least amount of obsticles on signal path =) This is a very capable motherboard & I doubt it would cause any issues, seen all the slots populated with GPUs working fine with 4g activated. As long as you provide enough stable/clean power this backbone should hold all Your system together without any issues. Booting/bios related stuff is another topic though..

I have tried the GPUs without cables and they work fine. It is deff the cables that cause problems, but it is hard to lock down which one is causing the issue. They all work fine until all 4 cards are plugged in at once. I do have 4G encoding enabled in the BIOS and have tried to go through and disable everything I'm not using. I have been troubleshooting the GPUs by themselves before installing additional addon cards. My power supply is EVGA T2 1600watt. What are some quality riser cables? I saw on overclock.net that cables did not make too much difference performance wise, but maybe it's an interference issue?

i use this cheap one, worked great.
http://www.amazon.com/Express-Riser-Ext ... detailpage

i have it before a splitter going to 4 980 ti's external.

it took me days to troubleshoot my multi GPU setup. the main thing i learned, on my MSI motherboard, was to keep completely resetting the BIOS every time i change anything. i had similar issues with windows 10, and bios failing to boot, but it all worked out and i can have 5 gpus now. im about to build a duplicate machine as soon as this gtx 1080 thing is figured out.

theres a lot i dont understand about it, but i just kept pushing forward. my best piece of advice is to keep super detailed hand written notes as you keep trying things
out. i have 14 pages of notes from that build and a few times i solved problems by going back to notes that seemed unimportant about what was in which slot, bios resets, win 10 behavior, etc.

best of luck!

for example, label those cables with numbers, and keep hand written notes about what happened with different combinations of things. its so tedious!