Try upping your shared memory and see if you see improved performance in your programs. You can also use benchmark programs to measure improvements.
I wouldn't be setting it to 128, that's the default for the laptopebackhus said:You may want to consider knocking that down as far as you can. The video you're working on won't reside in the card's allocated space so setting it for 128MB won't increase performance. You'd essentially be allocating RAM for no reason.