3 way sli on a GA-X99-UD4

[lerb50]

ANTEC 1200 HCP
GIGABYTE GA-X99-UD4 rev-1 LGA2011-v3
I7 5820K
EKWB CPU Cooler
Crucial M550 M.2 128 GB 3.0 SSD +2 WD blue 1 TB 3.0 .
16 gb G.Skill DDR4 2133
2 EVGA 780 6gb.sc watercooled in SLI
Creative Soundblaster Z 5.1
64 Bit Windows 7 Pro.
Corsair Air 540
Steelseries Merc Stealth Keyboard
Cyborg Rat 7
1,2,3, Sharp LC-32LE551U 32" tvs in Surround
#4 ACER V246HL


This is my hardware list My question is I acquired a 3rd evga780 6gb and I can't enable 3 way sli? The card displays and fans are working but I cant' enable 3 way ,2way works with 3 cards in. Is the motherboard causing this? As it is advertised to run 3way sli with a 5820k proc. Can you help? F12 bios.

[lerb50]

Re: 3 way sli on a GA-X99-UD4

* When an i7-5820K CPU is installed, the PCIE_2 slot operates at up to x8 mode and the PCIE_3 operates at up to x4 mode.
(All PCI Express x16 slots conform to PCI Express 3.0 standard.) - - -- -- - -- - Well I think I have found the problem 4X mode is not compatible with SLI u need 8x (I remember seeing this somewhere)...... Thanks GIGABYTE? And all the help on this forum. No really Does anyone Know anything about this?

[profJim]

Re: 3 way sli on a GA-X99-UD4

Nvidia requires an x8 slot for each video card in an SLI setup.
AMD does not have this requirement.

With your 5820K, you can't run 3-way SLI if you install one video card in the PCIE_3 (x4) slot according to the Gigabyte specs:
Did you try using the PCIE_1, PCIE_2 and PCIE_4 slots?

Gigabyte specs:

2 x PCI Express x16 slots, running at x16 (PCIE_1, PCIE_2)

• For optimum performance, if only one PCI Express graphics card is to be installed, be sure to install it in the PCIE_1 slot; if you are installing two PCI Express graphics cards, it is recommended that you install them in the PCIE_1 and PCIE_2 slots.

2 x PCI Express x16 slots, running at x8 (PCIE_3, PCIE_4)

• The PCIE_4 slot shares bandwidth with the PCIE_1 slot. When the PCIE_4 slot is populated, the PCIE_1 slot will operate at up to x8 mode.

* When an i7-5820K CPU is installed, the PCIE_2 slot operates at up to x8 mode and the PCIE_3 slot operates at up to x4 mode.

[profJim]

Re: 3 way sli on a GA-X99-UD4

If needed, see if you can manually set PCIE_1 to run in x8 mode in the bios.

[lerb50]

Re: 3 way sli on a GA-X99-UD4

Thank You for the answer. Yes I tried pcie 4 and it doesn't see the card. The million dollar question is how do I set the speeds of the pcie lanes?? I don't see an option for that anywhere. Other words I hafta get a 5930K...

[Chike]

Re: 3 way sli on a GA-X99-UD4

Do you use GC-3SLI bridge connector?

[profJim]

Re: 3 way sli on a GA-X99-UD4

Thank You for the answer. Yes I tried pcie 4 and it doesn't see the card. The million dollar question is how do I set the speeds of the pcie lanes?? I don't see an option for that anywhere. Other words I hafta get a 5930K...

Page 53 in your motherboard user manual says:

PCIe Slot Configuration

• Allows you to set the operation mode of the PCI Express slots to Gen 1, Gen 2, or Gen 3.
  Actual operation mode is subject to the hardware specification of each slot. Auto lets the BIOS automatically configure this setting. (Default: Auto)

Try enabling the Gen 2 setting to see if it helps.

Have you followed this step?

When two or more graphics cards are installed, we recommend that you connect the power cable from the power supply to the ATX4P connector to ensure system stability.

Are you using the GC-3SLI bridge?

[lerb50]

Re: 3 way sli on a GA-X99-UD4

Thanks for the reply. Yes I have the right bridge I even flipped it, and still no go. I have the 4 pin molex hooked up and tried gen2, and 3, and auto still no go. All cards work by themselves too. Is this false advertising on Gigybites part? Cause I can't get it to work. Ahh well I got @#$%&# again. (or is there hope)

[Chike]

Re: 3 way sli on a GA-X99-UD4

How do you use PCIE_3 with GC-3SLI or do you have GC-3SLI-X99 too?
There is no pint even trying it in PCIE_3 because it cannot work, in 3way sli all slots (1,4, & 2) should operate at x8.
Try to contact GB support and see what they have to say.

[lerb50]

Re: 3 way sli on a GA-X99-UD4

The motherboard and Nvidia control panel # the cards different than the slot #s the cards r in 1 2 & 4

[Chike]

Re: 3 way sli on a GA-X99-UD4

The motherboard and Nvidia control panel # the cards different than the slot #s the cards r in 1 2 & 4

Well you wrote PCIE_3 int post #2
Have you tried replacing the 3rd card with one of the two others?