Combining VRAM?

[golden citrus]

I recently got an RTX 4060 at a discount from a friend, but it only has 8GB of VRAM so while it's an improvement in some areas, it's a downgrade in others compared to my 3060 with 12GB. I still have the 3060, so I was wondering if there was any way to somehow combine the VRAM of the two GPUs to get the best of both worlds? I've heard about SLI, but I don't think either of my GPUs support it, so I was looking for an alternative. Thanks.

Here's my system info as well if you need it

[spark heath]

Is this for gaming?

[golden citrus]

Gaming and running AI models

[spark heath]

For gaming, no. For AI models, I have been told there is a way, but I don’t know if it’s possible with different cards

[golden citrus]

I was told I could run the GPUs in parallel to "double" my speeds, but it's not really the improvement I'm looking for when my 4060 takes triple the time to run a model over my 3060