is there any way to mod driver and get more dedicated memory?

Good, you will now probably have a better experience. I remember that at my older 4-series card it helped with YouTube video playback a lot. But make sure you don’t enable “Hardware Acceleration” at the browser as this card’s implementation is not working properly at all causing stuttering. Software is the only way to go, this gpu never had hardware acceleration so the newer modded drivers do show it’s compatible but you will only run into problems. Just sharing some of my personal experience with that card.

thanks for the tip.