Preparing for Occulus or similar...

Spirit_Retro

Limp Gawd
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Hi all,

I've nto been keeping up lately with the latest and greatest but I'm really hooked on playing Elite Dangerous. So I'm planning on entering the VR scene in a few months.

I already have an Asus GTX 980 STRIX. And I'm wondering- should I get a second for SLI or replace the card totally?

Just wondering what you guys think??
 
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Killa|3yte

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I'm assuming your 908 is indeed a 980.

From what I understand, SLI is not suited for VR and will not be for some time at least. The recommended GPU is a 970, which is a step down from your 980, so you are already in good shape.
 

Spirit_Retro

Limp Gawd
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I'm assuming your 908 is indeed a 980.

From what I understand, SLI is not suited for VR and will not be for some time at least. The recommended GPU is a 970, which is a step down from your 980, so you are already in good shape.

Thanks.. corrected that. :)
 

Nenu

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Yep, SLI is not supported.
I dont know if it ever can because it introduces lag and that is one of the biggest banes of VR.
It causes motion sickness and detracts from the immersion.

For the current gen at least, single card only, as fast as you need.
See how you fair with your 980.
 
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Ditto. Rift can't use SLI. (At least not yet - may be a while as latency issues prevent going there, so until Nvidia VR driver tech develops further and the Rift team decides to use it, well, it's single card use only.)

Hold onto your cash for Pascal in the Jul/Aug/Sept (somewhere in there) time-frame later this year. Enjoy the Rift with your 980 till Pascal arrives and then decide if Pascal is worth the $ or if you want to go SLI on your 980.
 

Anarchist4000

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Actually SLI/Crossfire should work relatively well for VR as you have 2 screens. AMD has also been timing their dual fiji release for VR and sticking dual cards in alienware systems for that very reason. Rift presents a really easy split screen SLI setup for developers.

The bigger problem is that all existing Nvidia cards have difficulty with the multi-threaded approach of DX12/Vulkan which is likely to be the foundation of VR.
 

Nenu

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Actually SLI/Crossfire should work relatively well for VR as you have 2 screens. AMD has also been timing their dual fiji release for VR and sticking dual cards in alienware systems for that very reason. Rift presents a really easy split screen SLI setup for developers.

The bigger problem is that all existing Nvidia cards have difficulty with the multi-threaded approach of DX12/Vulkan which is likely to be the foundation of VR.

Except it doesnt.
There is only one HDMI cable and no display driver to allow for simultaneous dual screen 3D output over 2 cables, each direct from a single GPU.
 

Anarchist4000

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VR SLI provides increased performance for virtual reality apps where multiple GPUs can be assigned a specific eye to dramatically accelerate stereo rendering. With the GPU affinity API, VR SLI allows scaling for systems with >2 GPUs. VR SLI is supported for DirectX and OpenGL Link
Well Nvidia seems to think otherwise. It's still one cable, but the VR headsets contain 2 screens with minor offsets for each eye. That's a pretty easy way to divide up the work for traditional (2 cards/GPUs) SLI. All that in WHQL driver last I checked as well.
 
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Anarchist4000

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Ok, edited my post to include a link to Nvidia's developer page. If by agenda you mean presenting facts for an argument I guess I'm guilty. Still no idea how an official Nvidia statement has nothing to do with Nvidia.
 

Nenu

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Ok, edited my post to include a link to Nvidia's developer page. If by agenda you mean presenting facts for an argument I guess I'm guilty. Still no idea how an official Nvidia statement has nothing to do with Nvidia.

Nvidia have not stated it is possible with the current driver to access 3D dual screens via 2 HDMI cables/2 connections.

You have been made aware that dual graphics cards add latency with one cable
In order to prevent this, dual interfaces to dual graphics cards are needed.
None of the VR headsets implement dual HDMI links.
You explicitly stated that Rift makes it easy to do this, it doesnt.

That is the minimum requirement.
Then the driver and developer need to utilise both connections.
 

Anarchist4000

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Nvidia have not stated it is possible with the current driver to access 3D dual screens via 2 HDMI cables/2 connections.

You have been made aware that dual graphics cards add latency with one cable
In order to prevent this, dual interfaces to dual graphics cards are needed.
None of the VR headsets implement dual HDMI links.
You explicitly stated that Rift makes it easy to do this, it doesnt.

That is the minimum requirement.
Then the driver and developer need to utilise both connections.

You are talking about an extremely insignificant amount of latency easily offset by the gains of nearly doubling your GPU power. SLI and Crossfire never would have made sense if your argument were true. There is no point in using multiple cables from different cards. VR almost exclusively will prefer SFR based approaches as you have two eyes.

For the Op, I'd recommend just waiting until the headsets are officially out. There is a benefit to SLI with VR, but a yet to be released card may serve you better. At the very least newer cards will push down the cost of another 980.
 

Derangel

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I'd say to wait for the Rift to release and see how things go. Even if SLI is technically supported that does not mean it will actually work properly out of the gate. For now it's probably best to stick with what you have until there is more information out there on just how much power CV1 really will need.
 

endlesszeal

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I maybe be wrong but I thought I read somewhere that sli is preferable to allow a gpu to render per eye.
 

Stanley Pain

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In the world of VR, FPS isn't the primary metric. Latency is. Motion to photon latency. It really needs to be under 20ms so any added latency be it CF or SLI can make or break the experience
 

Mr_Armageddon

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I will be getting rid of my liquid cooled GTX 580s in SLI solely for Oculus (pre-order completed). Been contemplating an upgrade for a while, but VR has pushed me to actually doing it. Gaming performance with the 580s was still pretty good, but I know SLI won't cut it for VR so making the much overdue upgrade.

As of this week started using an EVGA 970 FTW+, but planning on getting the X80 (GTX 1080?) Pascal SKU once waterblocks are also available, hopefully around summer time.

24377564406_7e481f2d00.jpg


One thing I was a bit concerned about was the Oculus System Compatibility Tool. Everything was green for me except my CPU. They recommend an Intel i5-4590 CPU or greater. Thing is my i7-970 although a few years old, actually beats the i5-4590 in most benchmarks (probably due to it being a hexacore CPU and OC'd to 4.2GHz). I'm hoping that it will still run everything ok, but worry about some sort of software limitation by Oculus that won't allow me to run the VR hardware because it doesn't meet their recommended spec.

23777187463_75fe85f0c4.jpg
 

Nenu

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It doesnt really matter.
Upgrade if you need to when you get it.
 

Mr_Armageddon

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It doesnt really matter.
Upgrade if you need to when you get it.

Hopefully that is the case. I'm fine with, and plan on, upgrading to Pascal once released. But not wanting to upgrade my CPU, as that would consist of a new Motherboard, RAM, waterblocks, etc. Looking for a few more years of life from that part of my current setup.
 

Dayaks

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Hopefully that is the case. I'm fine with, and plan on, upgrading to Pascal once released. But not wanting to upgrade my CPU, as that would consist of a new Motherboard, RAM, waterblocks, etc. Looking for a few more years of life from that part of my current setup.

Well doesn't hurt to try it with your current CPU. It will hold back Pascal to some extent. Especially since Occulus is 90Hz. Higher Hz takes a strong system all around. But hell you already have the system... And prices should come down the longer you wait.
 

Spirit_Retro

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Thanks for the comments guys. I'm gonna hold tight until there's a concrete need,

Much appreciated.
 

Blackstone

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Stick it out with the 980 but I expect you will want an upgrade when the successor to the 980ti hits. There is always going to be something faster around the corner. Just make sure you have enough VRAM for the type of anti-aliasing and similar features you want. The 980 is short on VRAM.

90Hz means you need 90 fps? That is a tall order for GTX 980.
 

dgz

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You are talking about an extremely insignificant amount of latency easily offset by the gains of nearly doubling your GPU power. SLI and Crossfire never would have made sense if your argument were true. There is no point in using multiple cables from different cards. VR almost exclusively will prefer SFR based approaches as you have two eyes.

For the Op, I'd recommend just waiting until the headsets are officially out. There is a benefit to SLI with VR, but a yet to be released card may serve you better. At the very least newer cards will push down the cost of another 980.

Ugh... anyone who listens to this guy is going to end up having a really bad time. Especially with VR.

Don't EVER trust people dismissing latency in any context but do actively run away if they're talking about games or, even worse, VR.
 

Nauseous

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i'd wait to see how vr does on your current rig before buying anything. easier to make a decision after you have used it to see how it feels.
 

Anarchist4000

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Ugh... anyone who listens to this guy is going to end up having a really bad time. Especially with VR.

Don't EVER trust people dismissing latency in any context but do actively run away if they're talking about games or, even worse, VR.

Well you'd be right if the <1ms to transfer half the scene from one GPU to another was more significant than cutting the time to render the entire scene roughly in half. But until VR starts requiring 1000+fps on current hardware I think my argument is fairly valid. Strange you say that yet both Nvidia and AMD are advertising dual GPU setups for VR. There are even tons of articles explaining why multiple adapters are better for VR.

https://developer.nvidia.com/virtual-reality-development said:
VR SLI provides increased performance for virtual reality apps where multiple GPUs can be assigned a specific eye to dramatically accelerate stereo rendering. With the GPU affinity API, VR SLI allows scaling for systems with >2 GPUs. VR SLI is supported for DirectX and OpenGL.
>2 adapters or uneven numbers is probably a bit questionable, but I guess it depends on the game.

VR SLI: Accelerating OpenGL Virtual Reality with Multi-GPU Rendering

Anandtech said:
This, in a nutshell, is why VR is the next great use case for multi-GPU setups. There is a significant performance need, and VR rendering is much friendlier to multi-GPU setups. RTG and NVIDIA are in turn both well aware of this, which is why both of them have multi-GPU technologies in their SDKs, Affinity Multi-GPU and VR SLI respectively.
AMD Dual-Fiji "Gemini" Video Card Delayed to 2016, Aligned With VR Headset Launches
Yes it's AMD, but they have one of the better slides I've seen explaining it. Same logic applies to Nvidia hardware.
 

noko

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Ugh... anyone who listens to this guy is going to end up having a really bad time. Especially with VR.

Don't EVER trust people dismissing latency in any context but do actively run away if they're talking about games or, even worse, VR.

If done right you will have decrease latency using dual GPU's. Both cards will be working on the same frame, one for the left eye, one for the right eye. It is then combined and displayed to the glasses. This is not alternate frame rendering which has different time spans in the game being rendered which incurs latency to user input.

Probably wait and see approach to see what one needs to get the most benefit out of it is more prudent. Plus how much game content, good content? will be initially available? I figure maybe by Christmas I will look into it plus by then all the next gen graphics cards, Zen, Intel Skylake E processor will be out etc. Plus maybe a few good VR games.
 

MorgothPl

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If you are wearing glassess, then you better check your frames compatibility with the headset. Not all of the frames fit the Occulus/Vive comfortably - was on Nvidia VR show, and some people had issues with using Occulus with spectacles - you have to first insert your glassess into headset, and then put it all on together.

Seriously, both those companies should take lessons from Playstation VR in terms of comfort.
 

wikidlad

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Quick question on the Rift for anyone that has tried it. How is the peripheral vision?, does the lenses fill your vision or is there "edges" that you see?
 

USMCGrunt

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Quick question on the Rift for anyone that has tried it. How is the peripheral vision?, does the lenses fill your vision or is there "edges" that you see?

Ive got a DK2, yes there are edges, the FOV is 110 degrees horizontally and vertically in the consumer release of the Rift. Our field of view is roughly 200 degrees horizontally, 120 of that is binocular (both eyes can see), and 135 degrees vertically. The cool thing though is that once you start using VR, you forget the edges are there for the same reason that you don't see your nose or eye socket all the time, your brain processes it out as irrelevant.


The last number I saw regarding latency was a roundtrip time of under 15ms from button press to on screen action...that's incredibly tight for all the rendering that has to be done. Although AMD has LiquidVR and Nvidia has VR SLI in the works to enable multi-gpu rendering in VR, it's not ready yet and we don't know when it will be. Oculus' official stance is that multi-gpu configurations are not supported, I'm unsure if HTC/Valve have made an official statement regarding this. Will SLI/CF setups work in game, probably. Will it be a pleasurable experience, maybe not.
 
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