GTX 1080 SLI makes no difference in Witcher 3

[Phoenix Fieryn]

Computer Type: Desktop

GPU: 2x GTX 1080 8GB no OC (factory OCed by ASUS)

CPU: Ryzen 7 1800X 4.0Ghz

Motherboard: ASUS Crosshair VI Hero latest BIOS (3008)

RAM: TridentZ RGB 32GB 3000Mhz (running 2800Mhz)

Disk: Samsung Evo 850 1TB, 2x Samsung 850 500GB (RAID 0), 3x 2TB Seagate HDD (RAID 0). Game is on the hard drive RAID.

PSU: EVGA 850 P2 Platinum 70.8A on 12V rail

OS: Windows 10 Pro 64-bit clean install (1709 16299.125)

GPU Drivers: 388.71 clean install

Description of problem: No noticeable gains from SLI in Witcher 3 1440p. Everything set to max (no hairworks) and FPS stays around 80 with either 1 or 2 cards. Focus monitor set properly. Monitor supports GSync and 165Hz. Vsync is off. Both cards are being utilized in Task Manager (95% 1st, 85% 2nd) when in SLI. 100% utilization in 1st GPU when not in SLI but FPS is the same. 3 monitors connected to the first GPU.

Troubleshooting: Set focus monitor on center monitor and I play using the center monitor. Clean installed the drivers. Used custom SLI profiles (0x280020F5, 0x280020F1, 0x280021F1). Set maximum performance and tried both SLI options in NVControl Panel (Force alternative frame 1 and 2).

 

Thanks

[m0k]

is it possible that somehow, the latest GPU drivers dont have SLI support or an SLI profile for Witcher 3? Did a bit of googling and it seems to be a common "issue" with this game

 

Perhaps look to install the "game-ready" driver that was launched with the Witcher 3 launch - perhaps that driver might work?

[FloRolf]

Wow, thank you for that all that information! Finally someone who does it right! 

 

Does sli work on other games? 

[DeadlyTitan]

most of the times a sli/crossfire isint going to give you a if any performance boost, its just a waste of money and well is the reason why single card solutions are better. Also the games must be explicitly written to support sli to take advantage of the sli. worst case scenario is some games even refuse to play good in sli and will be a shuttering mess forcing uses to disable sli and switch to single card. 

[Phoenix Fieryn]

6 minutes ago, mok said:

is it possible that somehow, the latest GPU drivers dont have SLI support or an SLI profile for Witcher 3? Did a bit of googling and it seems to be a common "issue" with this game

 

Perhaps look to install the "game-ready" driver that was launched with the Witcher 3 launch - perhaps that driver might work?

Thank you for the quick response. I will test the original driver for Witcher 3 though I am wondering if that will work with the GTX 1080 as that was not yet released back then? I'll do a little look around... perhaps the first GTX 1080 driver

4 minutes ago, FloRolf said:

Wow, thank you for that all that information! Finally someone who does it right! 

 

Does sli work on other games? 

Unfortunately, rarely. In regular SLI mode, I notice almost no gains in any games I play (like Battlefield 1). Though when I turn on Nvidia surround, I do get very good scaling in Battlefield 1. 

4 minutes ago, DeadlyTitan said:

most of the times a sli/crossfire isint going to give you a if any performance boost, its just a waste of money and well is the reason why single card solutions are better. Also the games must be written to support sli to take advantage of the sli. 

Yeah, I got the 2 GTX 1080s before the GTX 1080Ti existed. I'll be sure to get a GTX 1180Ti next time around. But Witcher 3 is known to have fantastic SLI scaling, even across 3 or even 4 GPU's... at least that's how it was a year ago...

[DeadlyTitan]

10 minutes ago, Phoenix Fieryn said:

Thank you for the quick response. I will test the original driver for Witcher 3 though I am wondering if that will work with the GTX 1080 as that was not yet released back then? I'll do a little look around... perhaps the first GTX 1080 driver

Unfortunately, rarely. In regular SLI mode, I notice almost no gains in any games I play (like Battlefield 1). Though when I turn on Nvidia surround, I do get very good scaling in Battlefield 1. 

Yeah, I got the 2 GTX 1080s before the GTX 1080Ti existed. I'll be sure to get a GTX 1180Ti next time around. But Witcher 3 is known to have fantastic SLI scaling, even across 3 or even 4 GPU's... at least that's how it was a year ago...

Assuming you have windows 10 then maybe its the windows 10 messing around? windows 10 is causing a lot of problems for a lot of users, you can find plenty of people with some sorta gaming related problem with windows 10 on these forums, i also had personal experiences where it really messed up my tools and some older games and drivers. 

 

I myself was a sli user once (back in the GTX 6xx series days) i stopped using sli when i realized i was not getting my moneys worth and am just throwing away money. sold off the 2 670's and bought a 780 and was never happy just my 2 cents 

 

 

[Phoenix Fieryn]

Ok wow I had to jump through a lot of hoops to get the original GTX 1080 driver installed. Windows kept automatically updating it.

 

And performance jumped to 90FPS now, interesting. A single card can only get 70FPS in this driver... Oh well, I really can't complain about it I guess. Thanks, guys

[gbergeron]

SLI sucks... unfortunately

[Phoenix Fieryn]

1 minute ago, gbergeron said:

SLI sucks... unfortunately

Please don't remind me haha. My 970 SLI actually worked fairly well (at least for me)... but they really seem to be phasing it out this time around. Really hope new games will support DX12 mGPU... I've got all these GPUs lying around, just mining rn.