I miss SLI.

[p0mpous]

It used to be supported pretty well and work in most games, I also used to love building and owning crazy PC's 2, 3 or even 4 GPUs in it, it just feels so boring to have a single GPU rig now.

[Coffee]

Problem is you need to win the lottery to buy 4 GPUs these days..

[ZeekAncient]

Me too. :( I never had 4 GPUs in at one time, but I did have two 1070s with a high bandwitdh bridge. Not only did it look awesome but when games took advantage of both GPUs, it was a beautiful thing. Better performance than a 1080Ti for less. But when it didn't work flawlessly, and you were forced to use Nvidia Profile Inspector to try to get a profile to run a game in SLi, and then it did, but it was a stuttery mess, it was awful. But a lot of games worked in SLi, especially the older ones. But I was starting to notice that a lot of the newer games weren't even making use of it anymore, or they did but you would only see like 60% usage on each GPU. But like I said, when you saw games get 100% usage on both GPUs, it was a beautiful thing. And my two GPUs with the awesome high bandwidth bridges just looked cool.

My current setup has a 3070Ti in it and it isn't even capable of doing SLi. Only 3090s can out of the 30 series. I guess it took Nvidia a long time to get wise. I mean back in the day, if you could get two midrange GPUs to outperform your flagship for less, what was the point. Like I said, my two 1070s outperformed a 1080Ti and only cost 800 total and a 1080Ti at the time was over 1000.

But yes, I miss SLi too :(...even if it was just my two GPU setup.

[Chill-Out-Zone]

4 GPU's? You can't rig more than 3 GPU's.

[Monk]

Originally posted by Chill-Out-Zone:

4 GPU's? You can't rig more than 3 GPU's.

You used to be able to.

Problem was support was dropped by the 20 series pretty much and there was no sli on unreal engine games and alot ran on those engines.

I ran 2 980's followed by 2 1080ti's.

A problem alot had us they never set the cards up properly so complained about stutter etc all the time which gave it a bad rep.

You can run 2 3090's now with nvlink, but there are no drivers for it.

A shame as I'd love to test it just for fun as I've got the cards abd they'll be in an x299 system so I have the bandwidth.

Not so keen on buying the £100 nvlink connector just to mess around gir a few hours though.

[ZeekAncient]

Originally posted by Monk:

A problem alot had us they never set the cards up properly so complained about stutter etc all the time which gave it a bad rep.

Well, I got stutter sometimes when I used an SLi profile on a game that otherwise wouldn't run in SLi. Sometimes if a game didn't recognize SLi, you could use Nvidia Profile Inspector to set it up with an SLi profile from another game that would work. But sometimes you got stutter.

But really what I was noticing the last few years, was that games used to fully make use of both GPUs. Like the Far Cry series or GTA 5, I got full GPU usage on both. But newer games while they made use of both GPUs, only made use of like 60% each GPU.

And also, Direct X 11 was needed to run in SLi. Direct X 12 or Vulcan, for me anyway, didn't recognize SLi. Maybe some games changed that. But I know with a game like Battlefield 1, I had to run it in DX11 to make use of SLi, while running in DX12 only made use of one GPU.

[_I_]

i miss the old voodoo sli (glide api) from way before nvidia took it over


back when the gpus worked together evenly to draw the frame
scan line interleave, where gpu 1 would draw even lines, and gpu 2 would draw odd lines
and output was a weave of the even + odd lines to make the entire frame

old sli, both gpus would need the same data in vram (cloned) since they are both working on different parts of the project


now sli is spreading out workload, but not done evenly, each does it own thing to complete the task faster, each will only have the vram data for the tasks its working on

sli now can let the gpus work different workloads, so 2x 8g gpus could let the task use 16g of vram, but workloads will be uneven between the gpus since they can do different things at the same time

[ZeekAncient]

SLi back then was Scan Line Interleave. That was 3dfx's SLi. Nvidia's SLi is Scalable Link Interface, lol. Nvidia bought out 3dfx anyway.

Speaking of which, how is AMD's crossfire? Is that still a thing as well?

[Lord Flashheart]

Originally posted by pompous:

It used to be supported pretty well and work in most games, I also used to love building and owning crazy PC's 2, 3 or even 4 GPUs in it, it just feels so boring to have a single GPU rig now.

Me too. I could help a lot with performance, but no longer supported.

I suspect in the near future, using multiple graphics cards could be useful again.
One for graphics render, and the other for AI upscaling calculations. We will see though.

[_I_]

amd crossfire works similar to nvidia sli
but amd does not need exactly the same gpu, similar can work

http://blogs.windows.com/wp-content/uploads/sites/2/2013/03/AMD_5F00_CrossfireX_5F00_Chart_5F00_1618W_5F00_67A9EF39.jpg

nvidia sli, both gpus need to be the same model, and if one is oc or higher clocked, it will be reduced to the lower cards speed

[p0mpous]

Originally posted by Chill-Out-Zone:

4 GPU's? You can't rig more than 3 GPU's.

No you could in the past.

[ZeekAncient]

Originally posted by _I_:

amd crossfire works similar to nvidia sli
but amd does not need exactly the same gpu, similar can work

http://blogs.windows.com/wp-content/uploads/sites/2/2013/03/AMD_5F00_CrossfireX_5F00_Chart_5F00_1618W_5F00_67A9EF39.jpg

nvidia sli, both gpus need to be the same model, and if one is oc or higher clocked, it will be reduced to the lower cards speed

No I know what crossfire is and how it worked. What I meant was, can use still crossfire with modern day AMD GPUs?

[_I_]

as far as i know, its not possible
you can have 2 gpus, and they can be set to different workloads for rendering jobs, but not tied together other than using the software