Yes it will with a game that has xfire support.
Have you had a 8350.
I don't need to have had an fx8350, to know that blanket statements are a fallacy.
You've literally made a statement that doesn't apply to all situations in the slightest. At 1080p, there will be a vast amount of games that simply don't run 99% on both gpu's on max settings in game.
I can accept some games may very well. In the same respect there are ones which don't.
Having owned both a 8350 and 7950 in crossfire (same system) i can say that i have experienced situations where the 7950 would be held back. One example was BF3 back when it was the main BF game, this was during Multiplayer 64 player.. That said i cannot say what patches have done nor drivers since then as i havent had that system for the last 2½ years.
How it performs in todays titles where a few are better threaded i also cannot comment on.