Looking at different reviews for the GT720 and it seems there are two versions , a 1gb ddr3 and 2gb gddr5 card . Depending on which one you have, you may have to drop the resolution down from 1920x 1080 to 1280 x 720 and see if it gets any better . you can always jump back up to 1366 x 768 and then to 1600 x 900 depending on what your frame rate does.
This Graphics Card has 2 variants: one paired with 1GB DDR3 and another with 2 GB GDDR5.
This is the DDR3 version.
GeForce GT 720 is a middle-class level Graphics Card still based on the 28nm, Kepler architecture.
GeForce GT 720 offers the energy optimized GK208 Core with a SMX count of 1 and thus comes with 192 Shader Processing Units, 16 TMUs and only 8 ROPs, this on a 64-bit memory of 1GB of standard DDR3. While the central unit runs at 797MHz, the memory clock operates at 900MHz. The rated board TDP is of 19 Watts.
GeForce GT 720's performance is therefore reduced and only on pair with today's most powerful integrated graphics.
This Graphics Card needs to be paired with a decent modern processor and should only be used on a gaming mode below 720p, for optimal performance.