2nd and 3rd GPUs NOT showing in Bios, but YES showing in Windows device manager, and YES working. HOW?!

OriKuper

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Feb 20, 2017
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Hello,

I'm attaching here the Asus diagrams and tables in the JPG, for reference.
My rig (originally, as a video/photo works station w/ adobe softwares):

Asus X99-A ii mobo (6 PCIE slots)
i7-6850 (40 lane max)
DDR4 3200 32GB
Gigabyte Nvidia GTX 1070 8GB
Win 10 Home

Few weeks ago I started playing around w/ mining altcoins, and I decided to get few more GPUs;
I ended up getting 2 GPUs to add to my computer, both are Zotec Nvidia 1060 3GB.

My original 1070 was, and stayed, in the top (first) PCIE 16 slot on the mobo.

By now I added one 1060 to the 4th slot on the mobo (directly into the PCIE 16), and one 1060 to the 6th slot, using a riser (so technically using a PCIE 2 connection, but inserted in a 16 slot).

Step 1: Added the first 1060. I Didn't change anything in bios. Win Device Manager (WDM) showed the 1060 as existing but w/ an error, and couldn't run it for mining. In other words it wasn't fully recognized by anything. I Then browsed around on the web, found bits of info, changed the PCIE slot _1 and _4 in the bios to X8 and X4, and BAM! it worked. Both the 1070 and 1060 were working. Great!

Step 2: Added the second 1060, on a riser, utilizing the last (bottom), 6th slot on the mobo. Nothing new showed in Bios (???), and yet both 1060s ares showing in WDM. Had to fiddle a bit w/ disabling and enabling, but now all the 3 GPUs are running while the computer is mining. Also great!

The things I'm trying to get explanations for, which might be very basic, are:

1. That change that I made in the bios, switching the 2 first pcies from Auto and Auto to X8 and X4 - what did that actually do? Why was it necessary?

2. Asus says that in order to use 3 GPUs, you should use a 40 lanes CPU. My CPU is 40 lanes max (and it shows as such in the bios), and yet, while I inserted the 3 GPUs by Asus directions (physical slots from top to bottom 1,4,6 = PCIE_1,3,4 logic), my bios still shows only 2 PCIE slots (_1, _4). Why does it not show the 3rd one? Or should it at all show it?

3. If the 3rd one doesn't show in Bios, how come WDM does recognize it, and that the computer can actually utilize them all while mining?

4. I understand that video editing stations (more specifically for me Premiere) - don't really like any SLI bridging connections. So I ain't gonna get one, BUT: Does anyone know if I can somehow utilize the power of the 3 GPUs while working on graphics stuff at all (Premiere, After Effects, Lightroom...)?

5. Even though the Bios did say somewhere '40 Lane Max' and made me understand it does recognize my i7-6850 as a 40 lanes CPU, it nowhere showed me an option of utilizing any of the PCIEs as X16. Just auto, X8 and X4. And yet in the Asus diagram and tables, where they show a 40 lane scheme, they show that a GPU or multiple GPUs, can and should be, utilized w/ something that got to do with PCIE X16. So... what am I missing?

6. Again - about that PCIE X16 mystery; does the fact that my first GPU (1070) was always on 'Auto' until now, means that it could and should have been working under some X16 instead? and could have been more powerful and faster for my video/graphic works???
If so - how do I get those sweet X16 (pun intended) speeds to life w/ my setup?

Sorry, I know it's a lot, but I believe it's all connected to each other. I'd appreciate any info and explanations. Feel free to quote and reply within, or however you like. Thanks!!

Ori.