from experience with a similar card, if you are plugging it in with VGA in Windows 8 (or 7) it won't let you selected 1920X1080 due to the VGA limitations. You will need to use DVI (even with a DVI to VGA adaptor) in order to get full 1080 resolution. HDMI will work as well if you have that option available to you.
There is no reason it should not work; lack of RAM would not be an issue.
I am assuming you had no issues running at 1440x900 60hz with your previous OS?
Thanks the version prefixed "13" worked, although I had to go into properties and view All Options to select the resolution and Hertz ... just selecting the resolution from W8 produced an error with the monitor. From the list of all options it worked OK