7-clown-7, thanks for entertainment, it is always amusing to see someone as utterly clueless as yourself talking with such confidence.
Now, to the point: to all who read and believed his posts, I strongly advice you to forget everything you just read, because it is wrong. In fact everything 7-clown-7 says is just his personal opinion, which he thinks is the ultimate truth. It is a lot more complicated than simply "your eye cannot see more than 30 fps", and I don't really see any point in explaining it all here, google is your friend.
What does matter though, for an ordinary player, is how many fps you feel comfortable with. If you feel 60 or 100 is the absolute minimum for a good experience, then it is, and it really doesn't matter that some random slowpoke says "no, you are fine at 30, anything above that is for epeen!!1".
Now if we go further, and consider a player who wants to perform well, or even be competitive, consider 60 fps as the absolute minimum no matter what it looks like to you (though if you can't tell the difference between 30 and 60 fps, I'd say you are a bit too slow to become very good), and 100 fps and above would be preferred.
So, in short, we really do need to be able to get high fps, by turning down settings or otherwise. Atm fps mostly depends on player count and presence of tanks and arty on the map, and it will be low regardless of graphics settings. So, twi, get optimizing!
P.S.
I advice against lowering number of channels from 32 because even 16 will cancel out a lot of relevant sounds. If it causes a problem, get a better sound card or something.