I'm guessing you may be on a laptop? Though the specs on those components sound good on paper, in practice they may be a bit on the low side for this game.

http://www.cpubenchmark.net/cpu.php?cpu=AMD+A8-5500+APU
http://www.notebookcheck.net/AMD-Rad...M.67752.0.html
http://www.videocardbenchmark.net/vi...HD+7470&id=298

Another thing you can look at for comparison is your Windows Experience Index (right-click the Computer Icon and select Properties). If you click on the hyperlink next to the score, it will give a detailed breakdown of your scores. 6+ in gaming graphics should be workable with tweaking, but to get a really good frame rate with XIV, you ideally want your gaming graphics score to be around a 7 or higher if possible. Just a note for people when shopping for systems--this is an easy way to get a glimpse of what to expect when comparing systems in the store.

You may need to run with a tweaked Laptop profile. Put everything you can on your graphics card's options to either Application controlled or a perfomrance/high performance setting. Then start with Standard Laptop settings in the game but turn off shadows for everyone, disable cascading shadows and glare points. If the physics options aren't already turned down for everyone but you, may want to notch them down as well. This should take out most of the "eye candy" in the game that may be challenging your APU to tweak out your frame rate, then you can turn things up from there if you find you have some wiggle room to improve quality a bit. One thing that may be working in your favor with this APU is you may have dedicated graphics memory (not sharing main memory)--but depending on what type and how much, you may still run into some constraints there. You can try toggling the LOD streaming option to see if it helps out any (may free up some memory usage).