Secondlife's graphic engine is more adapted to work with Nvidia's graphic cards. You can use other brands but at your own risk. The point is the support of OpenGL which not much brand still do today
NVIDIA control panel
Even if you get a good Nvidia card (like 1050 and ++) you can still improve the settings to have a better FPS in Secondlife. I tweaked a lot the Nvidia panel to have the best compromise. You can get your Nvidia control panel from desktop + right click. You can also define personalized settings for your Secondlife viewer.
Based on a 1080TI the listed settings:
What about SLI?
I tried myself to put 2 1080TI in SLI mode to see if you can get some improvement. For those who want to try it, don't forget to run Secondlife in full screen mode. In my case I only won maybe 2-3 FPS