|The CPU/board are about 5 years old & the 1156 platform was discontinued in 2012.|
Doubling up on the RAM would be helpful but the major weak point in your system is the video card. The 9500GT was an entry level card in 2008 & was never much good for gaming, especially the DDR2 version. Here's a comparison of the 9500GT to a modern entry level gaming card, the Radeon R7 250:
Have a look at this article: Best Graphics Cards For The Money: February 2014
"Edited the post it's 650watts"
Wattage doesn't tell us anything about the quality. What is the make/model of the PSU?