VR SLI ?

[aXeL]

Multi-gpu comes and goes. Right now it's definitely in a lull but I'll speculate that it will probably bounce back yet again. VR and Tablets came and went every ten years or so before they finally took root. On balance, I don't see the data in the article you cite agreeing with your or Wolfgang's statement. Some scaling was ok, some was very good. Also, he generalises quite badly, e.g:

"...in general, the dark cloud " micro-stutters " always hung over playing with multi-GPU systems - ie although there was very high FPS, the interval between the individual frames fluctuated strongly, which nevertheless as stammering made noticeable".

On my Xfire rigs - yup I agree 100%. On my SLI rigs - nope that statement is not true at all for me. In fact I recall precisely two scenarios on my SLI setups where it was still a problem, X3TC rolling demo where the ship left the huge ring station and far cry 2 benchmark test where the camera was panning smoothingly down a track before a few seconds of micro-stutter. Other than that, for the games I personally played, moving from XFire to SLI made frametime variance invisible to me.

Here's a slightly more objective analysis where the author does not, to me, appear to be expressing personal bias, with data from 11 contemporary games:
https://techguided.com/sli-vs-crossfire-is-it-worth-it/

 

[Masta Squidge]

Moreover, wasn't DX12 supposed to be able to aggregate disparate compute resources and pool them? This is where someone tells me ED is still on DX9 lol. Anyway, in this context, could a wrapper be used or would it be more plausible to go to Amazon and order unicorn laughter.. or ARX

That multiple GPU pooling idea never panned out, like a great deal of other useful features that were hyped up and aborted prematurely.

Nvidia has released SDK for VR sli some time ago > https://developer.nvidia.com/vrworks/graphics/vrsli

And yet there's a reason nobody is bothering with it to date.

Its not for lack of investment into multiple GPU technology. As I understand it, the issue affects the headset latency in such a way as to cause not only problems for the quality of the VR experience but physical discomfort. So everyone dropped support for VR/SLI pretty early on.

 

[Masta Squidge]

On my Xfire rigs - yup I agree 100%. On my SLI rigs - nope that statement is not true at all for me. In fact I recall precisely two scenarios on my SLI setups where it was still a problem, X3TC rolling demo where the ship left the huge ring station and far cry 2 benchmark test where the camera was panning smoothingly down a track before a few seconds of micro-stutter. Other than that, for the games I personally played, moving from XFire to SLI made frametime variance invisible to me.

That issue changes almost daily with variations in drivers, system performance, developer support (or lack of) and many other things.

Where you might see no microstuttering, someone else with the exact same rig playing the same exact game might have a horrendous experience. The cause for it still remains in play and until they somehow manage to synchronize two GPUs 100% without adding more than a fraction of a millisecond latency it will always be a real problem for some.

 

[aXeL]

That issue changes almost daily with variations in drivers, system performance, developer support (or lack of) and many other things.

Where you might see no microstuttering, someone else with the exact same rig playing the same exact game might have a horrendous experience. The cause for it still remains in play and until they somehow manage to synchronize two GPUs 100% without adding more than a fraction of a millisecond latency it will always be a real problem for some.

Totally agree, I think that's why I challenged the notion that it's generally bad for most/all

 

[Masta Squidge]

Totally agree, I think that's why I challenged the notion that it's generally bad for most/all

As an elitist jerk who hates having a full savings account I would love it if SLI was really viable for VR though.