I dont exactly understand what you mean by to start.
A comp can run of 512mb RAM. Even less. It will just be slow. What I wanted to say was that it depends on what you are doing. Generally, gaming, at this moment most mainstream games, dont require more than 4GB of RAM. If you want 8 gigs, go for it. But for gaming, the point of diminishing returns is around 4 gigs. I cant say for sure it will work simply because I havent had personal experience with this RAM
This person is using the exact same set with a 890GX chipset.
Ide say ur odds are verrryyyy goood using the 890FX with this set of RAM
Anyways, do you have a buddies comp you can test them out in?