Gtx 650 which works on mojave install saying kext not loaded on sierra/high sierra. Because I installed using integrated graphics?

I've heard it's meant to be supported natively in both sierra and high sierra but I'm only getting 1024x768 resolution and system reporter is saying it only has 4mb ram. It's definitely the 650 variant with native support as I dropped it into my mojave box - and with that one, I was able to go from integrated to the 650 even though I installed using integrated.