Hi Alan,

Like most CAD software SW demands a combination of ALL computer resources - RAM, Disc, Clock speed, etc. including hardware graphics, and you can't have too much of any of them.
In that respect CFD is no different.
I do most of my work (including some CFD stuff) on a good laptop equipped with an NVIDIA Quadro RTX 3000 graphics card. So far I haven't noticed that the graphics card is the bottleneck.
I have no experience with other graphics cards, so I can't compare. I would suggest you look at the SW web site to see what graphics cards have been tested and choose according to your budget, not your requirement to work with CFD.
BTW - The Quaro RTX was a very significant part of the cost of my laptop.

Jeffrey