8+ GPU BIOS hang issue on sabertooth 990fx r2.0 mobo

[ptunstall]

So I have the sabertooth 990fx R2.0 mobo and I have been using this pcie splitter for a while: http://amfeltec.com/products/flexible-x ... -oriented/.

I had a titan on the first PCIE
gtx 680 on the second PCIE
gtx 980 on the third PCIE
4-way splitter on PCIE 4 with:
gtx 680
gtx 980 ti
gtx 980 ti
gtx 980 ti

All was working fine and that configuration for whatever reason netted the highest score in octane bench, around 644.

NOW I ordered 3 more splitters and I added one more into the system in the 2nd PCIE. I hooked up another 980 ti and the 680 that was already there to it and now the BIOS hangs. IF I power down and turn off all power supplies for a bit and let the caps die off then turn it all back on, I'll get this error: "No physical memory is available at the location required for the windows boot manager. The system cannot continue" and if I reboot again BIOS goes back to hanging.

Most interesting thing is that as long as I keep my GPU count at 7, in that if I unplug ANY GPU not just one of the "newly added" ones, the system will boot up fine and windows will register the GPUs and octane will render without issue...

I am not attached to this MOBO by any means BUT I wanna know if I've hit some kind of limitation with AMD cpus or something else that I can't seem to find any info from googling...

My goal is to get 16 GPUs working on 1 MOBO and I have 12 ready to hook up.

I have a CNC mill that I am custom milling the case and frame with so everything can be caged and secured, have a cool design and nice cooling fan configuration. Just want to make sure the basics are going to work before I get into a full on handware building situation...

Any assistance is greatly appreciated!!!

[Lewis]

It's not gonna work wit 16 GPUs on same MB.

There is going to be problem with motherboard IRQs/resources and windows 7/8/10 rarely work with more than 8 GPUs anyway. Some special cases and server MBos (SuperMicro) can get it up to 10-12 but not many and not sucesfull for all users.

So if you want more you'll have to use network rendering and buy more octane FULL licenses Since Otoy still don't offer RenderSlave Lincenses .

[itou31]

Hi, do you have 4G decoding option in the BIOS ? activate it could help.
I have an P9x79 deluxe and able to manage 9 GPU only : viewtopic.php?f=25&t=45279&start=190#p270405
I think that 980Ti eat more ressources.

[Tutor]

Also, a system will tend to support more GPUs when running Linux than when running Windows and OSX. Does your 3d software run under Linux also?

[ptunstall]

This is all great info!!! I will definitely be switching to Linux for sure. We use it up at the studio I work for anyways so its nothing new. After reading all of your responses and doing more research I was wondering if its possible to disable things like USB, SATA, audio, etc controllers to free up BIOS IRQ allocation memory?

[ptunstall]

So I was able to get past the BIOS hang with 8 GPUs by turnung a bunch of stuff off but now windows won't initialize the 8th one... I tried Ubuntu and only 6 will get recognized before rebooting into ubuntu becomes impossible... I'll try that mint version although it says its based off of ubuntu so I don't know if I'll have any better luck...

Anyways I went ahead and pulled the trigger on getting this mobo: https://www.amazon.com/gp/product/B007K ... UTF8&psc=1
Along with 2 xeons... let's see where that gets me... Thanks for the help everyone!

[ptunstall]

So I've successfully hooked up 9 GPUs, (GTX 980 Ti), to the X9DRX+-F-O motherboard and 8 of those are on CPU1 while the last card is on CPU2. I'll continue adding GPUs till I either can't or reach 16 but so fars its working under linux mint. There was a TON of stuff to change in the bios as well as within linux... current score is 1105!!!!

[Lewis]

Have oyu enabled 4G Decoding in Bios to be able to do that 9 GPUs post/boot or was numerous of different settings?

ask 'coz Asus recommends using that option ONLY with TESLA GPUs and not "regular" GPUs.

[ptunstall]

Have oyu enabled 4G Decoding in Bios to be able to do that 9 GPUs post/boot or was numerous of different settings?

ask 'coz Asus recommends using that option ONLY with TESLA GPUs and not "regular" GPUs.

I did enable above 4G Decoding which basically allows you to address beyond beyond 32bits. I haven't flipped it off since I did a lot of other things so I donno what impact it has if any. I believe that we're in untested waters with some of this stuff so any and all "sure fire" info out there maybe untrue for what we're trying to do.

[Lewis]

Here is link to Asus FAQ/Manual which says it should be ON only for TESLA cards.

http://www.asus.com/support/FAQ/1004170 ... 1461515401