This message was posted on behalf of Intel Corporation
GPU overclock and increase video memory are couple of different things. Overclocking the graphics controller or the processor can damage those components, also, this will limit the life span of them.
With DVMT enabled you will add more shared memory to the graphics controller, this will increase game and programs performance.
Please check the following URL for more information about DVMT:
Thank you Alan, so increasing my shared memory size(DVMT) will not damage and limit the life span the components as GPU overclocking does?