Is my graphics card the bottleneck slowing down the pressure sensitivity on my graphics tablet? I have recently bought a pressure sensitive Huion 1060pro+ tablet. It's comparable to a medium-level Wacom.

On my Macbook Pro 15" 2009 the pressure sensitivity when working in Illustrator has a rather long lag, sometimes 15 seconds between pressing the pen down harder and the brush stroke becoming thicker. This is the same in both normal brush and blob brush, and Illustrator CC 2013 and CC 2015.

This delay does not happen on Photoshop, or on my girlfriend's Macbook Pro running Illustrator CS6. The hardware on my girlfriend's Macbook is comparable to mine, except for the graphics card - mine has a NVIDIA GeForce 9400M 256 MB, hers has an Intel HD Graphics 4000 1024 MB.

I'm thinking that perhaps my card can't process the changed shape of the vector quickly enough to provide an immediate response.

I'm interested in what you guys think, and if you have any suggestions for improving its performance short of buying a new laptop.
OK, so after upgrading my Macbook to something with much more horsepower the problem still existed, but to a lesser degree. I also updated Illustrator, but unfortunately couldn't roll back to CS6. 

The issue was lesser, but still a major problem. I just bought a similarly priced Wacom Intuos, and the experience is better in every way. No lag, perfect pressure sensitivity, and no sensation of long brush strokes becoming increasingly angular as they develop. Likely a poorly written driver from Huion - I would often find that pressure sensitivity would drop off the grid entirely until I restarted the driver process.

Moral of the story is not to buy Huion, unfortunately.