Intel Motherboards - SLI 2x on ASRock X99 OC Formula 3.1

SLI 2x on ASRock X99 OC Formula 3.1

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Category: Technical Support
Forum Name: Intel Motherboards
Forum Description: Question about ASRock Intel Motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=2722
Printed Date: 19 Jul 2025 at 8:30am
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Topic: SLI 2x on ASRock X99 OC Formula 3.1

Posted By: Karsten77
Subject: SLI 2x on ASRock X99 OC Formula 3.1
Date Posted: 25 May 2016 at 1:51am

Hello @all here in this forum,

recently i changed my Asus Mainboard and switched to a i7-5820K CPU with the Mainboard written in subject. I own a Gigabyte GTX 680 OC grafic card with 2048MB ram, and made the decision to upgrade to SLI insted to buy a new one. So i bought a used one same as mine. I use 64 GB of Corsair ram at 2800 MHz (Corsair Dominator Platinum DDR4 64GB).

Both cards i took in the #1 und #4 slot as described together with the bridge connector, as described in the manual ( http://asrock.pc.cdn.bitgravity.com/Manual/X99%20OC%20Formula3.1.pdf" rel="nofollow - http://asrock.pc.cdn.bitgravity.com/Manual/X99%20OC%20Formula3.1.pdf ).

When i revied the configuration, i noticed that one pcie slot is on x8, the other on x16. Both should be at x16, and yes its a 40 lanes pcie CPU. The SLI works of course, but maybe it can bring more performance.

Solved!

I also am unable to use this attached USB 3.1 card, or my old USB 3.0 card (i put it into slot #2, the black one, and tryed out also the other free slots). Simply not work, dont detect the card(s) or if detect, bluescreen. I run Windows 10 x64.

My question is, must i do any settings in the UEFI Bios? ~~There is an speed option for the pcie slots, its on auto, other values from gen1 to gen3 is there as an option. Is there an other option or a switch at the mainboard i have to set?~~

Oh and i have an M.2 Ultra Card as well attached, i read that the pcie slot #3 is not avail. But maybe it has something to do with that, i dont know. And the last information, i upgraded to the latest UEFI bios, ~~and i also reviewed that both grafic cards have the same bios, i had to update at least on sucessfully, now they are on the same bios version.~~

Maybe somebody may help here. Thanks in advance!

Karsten

Replies:

Posted By: Xaltar
Date Posted: 25 May 2016 at 2:17am

There is no performance to be gained by both cards being at x16. Even a GTX 980ti cannot saturate PCIe 3.0 x8 bandwidth so your SLI setup is operating as fast as your GPUs can handle as it is.

Your i7 5820k only has 28 PCIe lanes which is why you are not able to get x16 + x16 on your system. Only the i7 59XX CPUs have 40 PCIe lanes.

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Posted By: Karsten77
Date Posted: 25 May 2016 at 2:23am

Hello Xaltar,

thanks for the quick response! And you are right, its 28 lanes. My fault. Anyway the performance was raised to an level for me that i also was not worryed.

So this issue with my USB card is still there, do you have any ideas? That would be fine, because i have a lot of need for USB slots :).

Karsten

Posted By: Xaltar
Date Posted: 25 May 2016 at 3:01am

If you get the system to detect the card you get a BSOD (Blue screen)?

Try setting your system to boot into safe mode then shut down, install the card and boot into safe mode. Turn off safe mode again then reboot. If the BSOD is driver related that may solve the issue.

To allow the system to boot into safe mode:

1: Run msconfig.exe

2: Select the "boot" tab

3: Check "safe boot" and apply

When you restart you will boot into safe mode. Be sure you shut down rather than restart and install the 3.1 card before you boot into safe mode.

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Posted By: Karsten77
Date Posted: 25 May 2016 at 3:10am

Hello Xaltar,

i will test and check that tomorrow when am back at home. I will post the result asap i have any news. Thanks for your support!

Karsten