GDDR5 will always be better than GDDR3 in that the memory will be faster. (transfer rates roughly twice as fast) If you have your choice of the same card with either type, choose GDDR5 as long as it's not too expensive. This guy looks nice
and its the same price as other GDDR3 versions with its $20 MIR. The 6670 is the best card you can get right now that doesn't require external power.
Depending on how demanding your games might get in the future, why not bump right up against your budget ceiling with a 6770 for $100 after MIR?
The 6770 (or 5770, same thing) would probably sit at my "low-mid end gaming" recommendation. It should even give you decent 1920 x 1080 gaming performance
on the latest most demanding titles at medium quality video settings. You will need to connect it a 6-pin PCI power connector though so make sure thats possible for you before you buy.
Last edited by DPete27
on Thu Mar 29, 2012 6:49 pm, edited 1 time in total.
i5-3570K, ASRock Z77 Pro4-m, Asus GTX660 TOP, 120 GB Vertex 3 Max IOPS, 2 TB Samsung EcoGreen F4, 8GB G-Skill @1.25V, Silverstone PS07B