1080ti SLI in VR


#1

Hello everyone,
I know that we always heard alot about sli not being supported in vr and stuff…
Today I just tried it out as I got my 2nd 1080ti. Doing SLI with HB-bridge, then trying skyrim in vr, I was blown away by the difference, and its not even with native sli support. so dont believe what many have said, they obviously tried it with older cards.
I am saying this to lets those who ordered Pimax 8k x know, that this setup is most likely enough to power it.

Cheers


#2

I am sure many would welcome such development, but I had an SLI system once and it created more issues than it brought me any noticeable gain so I abandoned that concept again.

I would want to see it tried out with a whole range of games, learn more about the micro-stuttering issue and how it affects the user in VR (which would seem to make it even worse than in flatscreen gaming) etc…

Not trying to be negative, but I am certainly cautious. It would be cool if you could continue to report the performance with other games, and perhaps feed that with measured FPS and settings comparisons so we can quantify the advantage it offers a bit more. Is it 20 or 30 % more than with a single card, or does it do some magic and achieve a higher value proposition ?


#3

Thanks for the info! I’m planning to wait for the 1180Ti, but it’s nice to know that there are alternatives.


#4

I think its diffenetly more than 30%. I just played skyrim for like 10 minutes, and had the feeling that the limits of the game are reached, i.e. it cant run any smoother or better. The only issue was the rift resolution…


#5

So you are basically saying that Skyrim VR takes usage of SLI in VR? Wow thats some great news!
I have only one 1080 Ti now, but I remember a year ago when I had 2x980Ti SLI was impossible in VR except in Serious Sam VR.

Are there any links to some SLI testings with Skyrim VR, or any videos showing the difference?


#6

You are the lord of the tests mate :stuck_out_tongue:
Anyway I would be glad to do some basic benchmarks and keep u updated! I am not sure that skyrim has native sli support. I think its just a huge push due to base SLI function from geforce control pannel. I think software support would add alot more :wink:


#7

It will likely depend on the release. Both Unity 5.x? & unreal support sli/cf. But the game dev may need to enable.


#8

I do know on my old rig was 2x7950 in cf. Single card steamvr said don’t bother & no vr prog would launch. With them CF got 3.5 to odd 6.0 result. Programs & vr programs ran well at med settings o pimax 4k.


#9

You need to look at your gpu utilization of both cards. Are you using alternating frame rendering? Or are you saying skyrim vr has native sli implementation?


#10

sounds good, but rift resolution is not really that high, but still nice that with sli you can bump performance :smiley:

and resolution is what is gonna draw a lot of power because you got more pixels to fill etc

can you see how much fps you getting? max fps of HMD?
might not be the case you can get max fps with 8k , but if you could, that would be pretty awesome it means, within a 2 year period we will have single cards that can power up 4k easily for max settings any game you throw at :smiley:


#11

can you please try it out with other vr games other than skyrim…? maybe fallout vr, or anything else that doesn’t support SLI


#12

Your mistaken. I asked someone with two 1080tis to test it out with afr so that it would force both cards to work and it caused reprojection spikes and no performance increase.


#13

Either way looks like it might be doing something. See below steam discussion. Looks like someone else is reporting with dual 980s.

https://steamcommunity.com/app/611670/discussions/0/1696043806558606406/


#14

Why bother with 1080ti sli when you can 1180


#15

have you read 1180 spec ? This card is not going to be stronger than for example Asus 1080ti


#16

Any newer GPU will only see around 25->35% perf improvement, especially now that current technology is fast approaching the physical limits of current silicon chip architecture, while a SLI configuration even of previous generation cards gives almost double the performance if running on a SLI supported application or dual screen setup.

So in a sense…better to have two 1080Ti SLI than a newer GPU, if supported from the application you’re going to use.


#17

The problem is that SLI mode isn’t universally supported. I’ve read the 1180 specs, which is why I’m planning on getting an 1180Ti as my next GPU. I currently only have a 980Ti, but I’d rather wait a bit and get a card which I can use for a long while.


#18

Few years back. I had two 780ti in SLI. i thought the graphical power was enough even when i receive my then brand new HTC vive pre-order May 2016. With all the promises of VR SLI support etc etc etc. SLI for VR pretty much never happened, Then came the 9 Series, never happened then as well, Then came the 1080. I couidn’t wait any longer i got the 1080… i thought by then i could add a second 1080 if i needed more graphical power, after all so much time has passed by they should have SLI supported by now… ok that never happened as well. Now im using a single 1080ti… You get where this is going. No doubt i will be getting the 1180Ti when it releases and not looking back.


#19

no… i would assume its better than a 1080ti?
if not i guess 1180ti is where my money is at.


#20

With all the money and effort nVidia spends for getting GameWorks FX into AAA titles to make their GPUs shine it’s somewhat obvious that SLI for VR is not really on their priority list. They don’t need to, because as long as AMDs alternatives are not faster as single or dual GPU setup they rather keep us waiting and sell next gencards w/o additional software efforts.

It all would change the day when Bethesda and id software would start to implement LiquidVR dual GPU for AMD, then nVidia would have to bring in their engineers to make their SLI VR work as well.
But at the moment I think AMD is not pushing money into this, they might rather focus on future designs where dual GPUs are transparent to the OS and software.

But one wonders also for the VR runtimes, when these do a monitor output and HMD output at the same time what an additional GPU could help there to some extend.