Motherboard bottleneck?

Since you are gaming I would go the Intel route with CPU/MOBO and new RAM. It will make a world of difference in your gaming. Here are some thoughts:

Intel Core i5-3570K Ivy Bridge 3.4GHz $219
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

GIGABYTE GA-Z77X-D3H LGA 1155 Intel Z77 $153
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

MSI Z77A-G43 LGA 1155 Intel Z77 $109
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 $44
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Well micro-stutter is normally associated with xfire/SLI setups since your isn't the next questions is what games are you playing that you have frame rate problems and what resolutions are you playing ? You also need to state what your CPU is running at and if it OC or not.

The cpu is stock speeds with a 212EVO on it.

I play just about any game released in the last 12 months with the exception of Assassin's Creed III. Everything runs subpar at 1920x1080. I never turn on AA. Ever. In fact, FPS and stuttering remains consistent from bare minimum detail settings to ultra. The only setting that ever affects performance is if a game has physics settings. Turning to low always increases performance.

I have old DDR2 ram and the stuttering feels like the machine is polling the hard drive to load new textures into memory. That is my best guess because when I spin around in circles a few times it goes from 10FPS to well above 120 and stays smooth unless there are a lot of particles/ moving objects or I am entering places with new textures popping in.

I would prefer to stick with my current system if there is anything I can do to salvage it. Benchmarks lead me to believe that switching to Intel would be a huge investment with a minimal increase in perceived performance. I can upgrade to a DDR3 board and get 1600 memory in the 8gig depart for under 150. Going to intel would be at least 300. I really wish there was a way to see two identical machines in action, but unfortunately, I don't know anyone with two setups to compare. Thoughts?

keep that processor. you may upgrade to an AM3+ board with DDR3 ram support but that wont take your performance up by a lot. which catalyst version are you using? your system should perform quiet well especially with that gpu. run furmark or another similar gpu testing/benchmarking tool to check whether your gpu is performing as expected.

I am running 12.10 on Win8.

I just ran Furmark. 1080 bench puts me at 1767. The score for their site is 1767 as well. Is there a general benchmark I could use to kind of gauge my system?

I asked for the catalyst version because i read here on toms how 12.10(i think, or may be another higher version) was extracting the best out of amd cards. If your furmark score is same as that for other cards there then i think you are set in this department. One another way of testing your full set up would be to bench it on 3D mark 11.

go for the free version and you'll be able to test at a medium preset. at the end of the test it will open the 3D mark 11 website for score comparison and you would be seeing you scores for cpu and gpu and some other system components as well. you'll get an idea of which components are holding you back.

if you see my sig, you'll note that i run my i5 downclocked to 2 GHz. i get a message on their website which tells me your cpu physics score is lower than expected and when i run the cpu on default clocks, i get the expected scores. This way you'll know if your card/proc is underperforming or not.