Question Can you game on a multi-gpu system?

[Gamefreaknet]

Hi. I have noticed on multiple sites there are GPU's like the 980ti, 1070 and other similar GPUs going at around £100 - £250ish which is currently a ton cheaper than most of the new RTX 30 series and a fair few of the RTX 20 series lineup however could (for example) pairing 3 or 4 GTX 980ti's provide performance say around the margins of maybe a 1660 or even a 20 series card? Also would this allow these multiple GPUs be able to work together to more efficiently attempt things like Antialiasing, Ray Tracing and other such features that almost exclusively RTX cards can do due to the power or is it merely based around how the cards were made and designed that prevents these older GPUs handling Ray Tracing and other such features found in the RTX series?
Final Question... Can you mix GPUs on the same system (so like a GTX 1080ti paired with a GTX 980ti)?
I assume any system like this if possible would also require a fair load of RAM (probably at least 32GB 3200mhz) and likely higher than an i5 8th Gen+ or i7 4thg gen+ with overclocking capabilities?

 

[kerberos_20]

SLI is discontinued
you can run multiple GPUs under DX12 as long game supports it
are there any? not many, ashes of singularity comming to mind, but that one doesnt like when gpus have different level of performance
but DX12 can support such combinations, its just up to game developers to utilise it...and nobody really bothers now

 

[kerberos_20]

here is some list of dx12 explicit m-gpu games

DX12 or Vulkan Games Supporting m-GPU

Is there a better list to be found anywhere on the internet? I don't mean Crossfire or SLI support, but via DX12/Vulkan explicit m-GPU. As far as I know there is currently: - 1. Ashes Of The Singularity...

forums.tomshardware.com

 

[XxDarkMario20xX]

Do not think you can SLI with two diffrent cards has to be the same one you have now so 1070 has to be paired with 1070 and such and also SLI is kinda pointless now in games since there not supporting it much now days. Would suggest finding GPU that can play your games at good FPS and such!