3-way 780 TI or 1x 980 TI?

[TheNaitsyrk]

Hi,

I have a hard decision to make, since I have 2x 780 TI and I'm getting 45-50 FPS on Ultra Witcher 3, and I would get 32-35 on Ultra Witcher 3 I need to know which one would be better.

Should I 3-way SLI my 780 TI to get 60 FPS on 4K, or should I sell my 2x 780 TI and just get 1x 980 TI? (Lower chances of upgrading (SLI) in the future).

Also, what PSU would I need for triple 780 TI + room for overclock?

I have 4790K, Z87X-OC-FORCE mobo etc.

 

[MarkW]

1 GTX 980 will have none of the SLI issues that tend to pop up. And will use less power too.

 

[TechyInAZ]

Defiantly go with single GTX 980 ti. The 3GB vram is probably continuing to bottleneck your GPUs.

 

[TheNaitsyrk]

Nope, I got no stuttering on 4K. Like I said, 980 TI gets 32-35 FPS and I'm getting 45-50. With 3rd one would I get 60?

 

[MarkW]

No can do. You would need to be using an X99 motherboard and CPU to go three way SLI.

Nvidia requires 8 PCIe lanes per card, and the all of the Z#7 boards only get 16 lanes. Soon as you plug in a 3rd card, the 2nd slot splits its 8 lanes with the 3rd card, so you have 8x/4x/4x and the SLI drivers put the 2 cards on 4x lanes on standby.

 

[TheNaitsyrk]

My motherboard can do Quad SLI.... https://www.youtube.com/watch?v=ATqVmge-DJA

 

[MarkW]

Yes it can. But you need to buy a pair of cards that are SLI unto themselves, and SLI those. Still 2 cards. Like the AMD's R9 295X.

 

[TheNaitsyrk]

I'll check this. Pretty sure I can add another one safely. They WOUDLN'T ADD 3 way SLI bridge and 4 way SLI bridge with the motherboard if I wasn't able to you know?

 

[MarkW]

16 / 2 = 8. 3 way SLI requires 8 lanes per card. you do not have 24 lanes of PCIe to share.

1 card = 16x/0x/0x
2 cards = 8x/x8x/0x
3 cards = 8x/4x/4x

The red lanes cannot function in SLI mode.

 

[TheNaitsyrk]

Documentation says I can run Quad and I even have OC brace for it to hold 4 GPUS. https://www.youtube.com/watch?v=ATqVmge-DJA NOW WATCH CAREFULLY 7:45 -->

 

[bystander]

Are you planning to water cool your 780's if you go with 3-way SLI? If not, things are going to get hot and noisy.

You might also need to know that 3-way SLI has 3 times the latency that a single card would when getting the same FPS. That also means that when you are not getting good or poor scaling, you are increasing your latency.

You may also consider just lowering some settings to get good FPS.

 

[TheNaitsyrk]

I considered it, but I just want to get 60 FPS on 4K without using £1100 on new 980 TI SLI. This is why I created this thread. Keep trying to sell my SLI 780 TI so I can eventually buy 980 TI, or keep them and go 3 way SLI. Chances to upgrade 980 TI SLI are rather low for me.

 

[MarkW]

I just read the manual that gigabyte has up for your motherboard.

In 3 places I see them say they support 2/3/4 way SLI.

Then when they get to how to do it in section 1-6, on page 19, they once again repeat the 2/3/4 way SLI mantra. And the right below that, they tell you how to set it up, and I will cut and paste the entire portion describing how to install the cards for this. Please pay special attention to step 1:

A. System Requirements
- Windows 8 or Windows 7 operating system
- A CrossFire/SLI-supported motherboard with two or more PCI Express x16 slots and correct driver
- CrossFire/SLI-ready graphics cards of identical brand and chip and correct driver
(Current GPUs that support 3-Way/4-Way CrossFire technology include the ATI Radeon™ HD 3800, HD 4800, HD 5800 series, and AMD Radeon™ HD 6800, HD 6900, HD 7800, and HD 7900 series. Current GPUs that support 3-Way/4-Way SLI technology include the NVIDIA® 8800 GTX, 8800 Ultra, 9800 GTX, GTX 260, GTX 280, GTX 470, GTX 480, GTX 570, GTX 580, GTX 590, and GTX 600 series.) For the latest GPU support information, please refer to the AMD/NVIDIA® official website.)
- CrossFire (Note)/SLI bridge connectors
- A power supply with sufficient power is recommended (Refer to the manual of your graphics cards for the power requirement)
B. Connecting the Graphics Cards
Step 1:
Observe the steps in "1-5 Installing an Expansion Card" and install CrossFire/SLI graphics cards on the PCI Express x16 slots. (To set up a 2-Way configuration, we recommend installing the graphics cards on the PCIEX16_1 and PCIEX16_3 slots.)
Step 2:
Insert the CrossFire (Note)/SLI bridge connectors in the CrossFire/SLI gold edge connectors on top of the cards.
Step 3:
Plug the display cable into the graphics card on the PCIEX16_1 slot
C. Configuring the Graphics Card Driver
C-1. To Enable CrossFire Function
After installing the graphics card driver in the operating system, go to the Catalyst Control Center. Browse to Performance\AMD CrossFireX™ Configuration and ensure the Enable CrossFireX™ check box is selected. Select the GPU combination you want to use and click Apply. (Available combination options are dependent on the number of graphics cards.)
C-2. To Enable SLI Function
After installing the graphics card driver in the operating system, go to the NVIDIA Control Panel. Browse to the Configure SLI, Surround, Physx screen and ensure Maximize 3D performance is enabled.

(Note) The bridge connector(s) may be needed or not depending on your graphics cards

I don't know what else to tell you. I have been building, fixing and everything else with computers for 35 years.

You could do a 3 or 4 way SLI on a motherboard that had enough Plex Switches to make the motherboard share the PCIe lanes, but your motherboard does not have any of those. And I have not seen a new Plex Switch motherboard come out in years. The only other way to do it is to have a 2011 socket motherboard with the I7-58xxX CPU, which come with either 24 lanes or 40 lanes, depending on the CPU.

I am going to bow out at this point. I have explained everything there is to explain. Further participation by me in this thread would gain nothing.

 

[athol]

What resolution are you playing at? @ standard hd one 980 is sufficient for ultra.

 

[bystander]

I just read the manual that gigabyte has up for your motherboard.

In 3 places I see them say they support 2/3/4 way SLI.

Then when they get to how to do it in section 1-6, on page 19, they once again repeat the 2/3/4 way SLI mantra. And the right below that, they tell you how to set it up, and I will cut and paste the entire portion describing how to install the cards for this. Please pay special attention to step 1:

A. System Requirements
- Windows 8 or Windows 7 operating system
- A CrossFire/SLI-supported motherboard with two or more PCI Express x16 slots and correct driver
- CrossFire/SLI-ready graphics cards of identical brand and chip and correct driver
(Current GPUs that support 3-Way/4-Way CrossFire technology include the ATI Radeon™ HD 3800, HD 4800, HD 5800 series, and AMD Radeon™ HD 6800, HD 6900, HD 7800, and HD 7900 series. Current GPUs that support 3-Way/4-Way SLI technology include the NVIDIA® 8800 GTX, 8800 Ultra, 9800 GTX, GTX 260, GTX 280, GTX 470, GTX 480, GTX 570, GTX 580, GTX 590, and GTX 600 series.) For the latest GPU support information, please refer to the AMD/NVIDIA® official website.)
- CrossFire (Note)/SLI bridge connectors
- A power supply with sufficient power is recommended (Refer to the manual of your graphics cards for the power requirement)
B. Connecting the Graphics Cards
Step 1:
Observe the steps in "1-5 Installing an Expansion Card" and install CrossFire/SLI graphics cards on the PCI Express x16 slots. (To set up a 2-Way configuration, we recommend installing the graphics cards on the PCIEX16_1 and PCIEX16_3 slots.)
Step 2:
Insert the CrossFire (Note)/SLI bridge connectors in the CrossFire/SLI gold edge connectors on top of the cards.
Step 3:
Plug the display cable into the graphics card on the PCIEX16_1 slot
C. Configuring the Graphics Card Driver
C-1. To Enable CrossFire Function
After installing the graphics card driver in the operating system, go to the Catalyst Control Center. Browse to Performance\AMD CrossFireX™ Configuration and ensure the Enable CrossFireX™ check box is selected. Select the GPU combination you want to use and click Apply. (Available combination options are dependent on the number of graphics cards.)
C-2. To Enable SLI Function
After installing the graphics card driver in the operating system, go to the NVIDIA Control Panel. Browse to the Configure SLI, Surround, Physx screen and ensure Maximize 3D performance is enabled.

(Note) The bridge connector(s) may be needed or not depending on your graphics cards

I don't know what else to tell you. I have been building, fixing and everything else with computers for 35 years.

You could do a 3 or 4 way SLI on a motherboard that had enough Plex Switches to make the motherboard share the PCIe lanes, but your motherboard does not have any of those. And I have not seen a new Plex Switch motherboard come out in years. The only other way to do it is to have a 2011 socket motherboard with the I7-58xxX CPU, which come with either 24 lanes or 40 lanes, depending on the CPU.

I am going to bow out at this point. I have explained everything there is to explain. Further participation by me in this thread would gain nothing.

There isn't anything in that setup description that has anything to do with how many cards it'll support. It merely suggested using PCIe 1 and 3 if in 2-way SLI. I suspect they tell you to use those due to both circulation, but perhaps due to them supporting more lanes on those 2 slots.

 

[TheNaitsyrk]

I'm playing at 4K and bystander is correct. I browse web far and wide and it says I can do 4x x8 PCI-E. I'm using 1 and 3 because I don't want GPUs to be too close to one another. http://www.gigabyte.com/products/product-page.aspx?pid=4484#ov
"Premium 4-way Graphics Support:
This extreme design employs a PLX chip that doubles the available PCI Express bandwidth, allowing overclockers and gamers to enjoy the ultimate in extreme multi-GPU configurations; 4-way AMD CrossFire™ and NVIDIA SLI."

"3 x PCI Express x16 slots, running at x16 (PCIEX16_1~3)
2 x PCI Express x16 slots, running at x8 (PCIEX8_1~2)

2 x PCI Express x1 slots"

35 years experience, SURE HA. Another proof: http://www.overclock.net/t/1560075/z87x-oc-force-motherboard-can-i-3-way-sli

 

[MarkW]

http://www.tomshardware.com/reviews/nvidia-sli-faq,4079.html

 

[TheNaitsyrk]

"yes you can, the board has a PLX chip which gives more pci-e lanes so you can run more than two nvidia cards on it.

it will run 16 x 8 x 8"

"You'll either need an LGA 1150-based board equipped with an (expensive) PLX bridge chip or an even more expensive LGA 2011-v3 platform if you want to go beyond two-way SLI."